Composition having refractive index sensitively changeable by radiation and method for forming refractive index pattern

ABSTRACT

A radiation sensitive refractive index changing composition comprising (A) a decomposable compound, (B) a non-decomposable compound having a lower refractive index than the decomposable compound (A), (C) a radiation sensitive decomposer and (D) a stabilizer. By exposing the composition to radiation through a pattern mask, the above components (C) and (A) of an exposed portion are decomposed and a refractive index difference is made between the exposed portion and unexposed portion, thereby forming a pattern having different refractive indices

DESCRIPTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a radiation sensitive refractiveindex changing composition, a refractive index pattern forming method, arefractive index pattern and an optical material. More specifically, itrelates to a novel radiation sensitive refractive index changingcomposition which is used in the optoelectronic and display fields, arefractive index pattern forming method, a refractive index pattern andan optical material.

[0003] 2. Prior Art

[0004] In the current society called “multi-media society”, refractiveindex distribution type optically molded products each consisting ofdifferent refractive index regions are in great demand. The productsinclude not only optical fibers for transmitting information but alsooptical diffraction gratings having a periodical change in refractiveindex, optical memories to which information is written at sites havingdifferent refractive indices, optically coupled elements such as opticalIC's having a fine refractive index pattern, optical control elements,optical modulation elements and optical transmission elements.

[0005] The refractive index distribution type optically molded productsare divided into two types: one having a continuous refractive indexdistribution, such as GI type optical fibers (to be referred to as “GRINoptically molded products” hereinafter) and the other having adiscontinuous refractive index distribution, such as optical diffractiongratings and SI type optical waveguides.

[0006] The GRIN optically molded products are attracting much attentionas the next-generation optically molded products. For example, a GI typeoptical fiber whose refractive index is reduced from the center axis ofthe core of the optical fiber to the periphery in a parabolic formenables the transmission of a great volume of information. A GRIN lenswhose refractive index continuously changes therein is used as a readinglens for use in copiers, spherical lens for connecting fibers, ormicro-lens, making use of its characteristic features that it hasrefractive power even with a flat surface and that it is free fromspherical aberration.

[0007] A large number of methods of producing the above GRIN opticallymolded products have been proposed up till now. For example, JP-A9-133813, JP-A 8-336911, JP-A 8-337609, JP-A 3-192310, JP-A 5-60931 (theterm “JP-A” as used herein means an “unexamined published Japanesepatent application”), WO93/19505 and WO94/04949 disclose a method ofobtaining a GI type optical fiber by dispersing low molecular weightcompounds or a monomer into a polymer and continuously distributing itsconcentration. JP-A 62-25705 discloses that a GI type rod-like opticallymolded product or optical fiber is obtained by photo-copolymerizing twoor more vinyl monomers having different diffraction indices andreactivity rations. Further, JP-A 7-56026 discloses a method ofobtaining a refractive index distribution by forming a polymer A havinga photo-reactive functional group, dispersing a compound B having alower refractive index than the polymer A into the polymer A to form theconcentration distribution of the compound B and photo-reacting thepolymer A with the compound B.

[0008] Some methods of producing GRIN optically molded products of aninorganic material have also been proposed. One of them is, for example,a method of producing a GI type rod by adding high-refractive indexthallium to rod-like glass essentially composed of silicon or lead,immersing the glass in a molten solution containing low-refractive indexpotassium, and forming a potassium concentration distribution by ionexchange.

[0009] A GRIN lens can be obtained likewise by applying the above methodto a short rod, that is, lens-like optically molded product.Alternatively, the GI type rod produced by the above method may besliced.

[0010] As one of methods of producing an optically molded product havinga fine refractive index pattern, such as the above optical diffractiongrating or optical IC, there is known a technology for obtaining achange in refractive index by causing a photochemical reaction in amolded product by the irradiation of light. For instance, in the case ofan inorganic material, glass doped with germanium is irradiated withlight to change its refractive index to produce an optical diffractiongrating. In the case of an organic material, the above technology isknown as a photochromic reaction or photo bleaching and JP-A 7-92313discloses a technology for obtaining an optical diffraction grating bycausing a change in refractive index by irradiating a materialcontaining low molecular weight compounds having photochemicalreactivity dispersed in a polymer with a laser beam. Further, JP-A9-178901 has recently proposed that this technology is applied to theproduction of a GRIN optically molded product. This method provides acontinuous refractive index distribution in a depth direction withrespect to irradiation, making use of the fact that light irradiatedonto a molded product is absorbed and weakened in intensity.

[0011] However, in the refractive index distributions obtained with theabove conventional materials, the maximum refractive index difference isabout 0.001 to 0.02 and it is difficult to provide a wider refractiveindex distribution in order to prevent an optical loss and suppress themalfunction of a circuit.

[0012] When the above conventional materials are used under thecondition that light having a wavelength close to the wavelength usedfor changing the refractive index passes therethrough after a refractiveindex distribution is formed, it is impossible to prevent such aphenomenon that a gradual change in refractive index occurs, therebydeteriorating the materials.

SUMMARY OF THE INVENTION

[0013] The present invention has been made in view of the above problemsof the prior art.

[0014] That is, it is an object of the present invention to provide aradiation sensitive refractive index changing composition whoserefractive index of materials is changed by a simple method, whosechanged refractive index difference is sufficiently large, and which canprovide a stable refractive index pattern and a stable optical materialregardless of use conditions.

[0015] It is another object of the present invention to provide aradiation sensitive refractive index changing composition which formsfine pores upon exposure to radiation, retains the formed fine poresstably, and provides a refractive index pattern having high filmstrength although it has a large number of fine pores.

[0016] It is still another object of the present invention to provide amethod of forming a refractive index pattern from the above compositionof the present invention.

[0017] It is a further object of the present invention to provide arefractive index pattern or an optical material produced by the abovemethod of the present invention.

[0018] Other objects and advantages of the present invention will becomeapparent from the following description.

[0019] Means for Solving the Problem

[0020] According to the present invention, firstly, the above objectsand advantages of the present invention are attained by a radiationsensitive refractive index changing composition comprising (A) adecomposable compound, (B) anon-decomposable compound having a lowerrefractive index than the decomposable compound (A), (C) a radiationsensitive decomposer and (D) a stabilizer.

[0021] Secondly, the above objects and advantages of the presentinvention are attained by a refractive index pattern forming methodcomprising exposing a radiation sensitive refractive index changingcomposition comprising (A) a decomposable compound, (B) anon-decomposable compound having a lower refractive index than thedecomposable compound (A), (C) a radiation sensitive decomposer and (D)a stabilizer to radiation and heating to react the stabilizer (D) withthe decomposable compound (A) of an unexposed portion.

[0022] Thirdly, the above objects and advantages of the presentinvention are attained by a refractive index pattern forming methodcomprising exposing a refractive index changing composition comprising(A) a decomposable compound, (B) a non-decomposable compound having alower refractive index than the decomposable compound (A) and (C) aradiation sensitive decomposer to radiation through a pattern mask andtreating the composition with (D) a stabilizer to react the decomposablecompound (A) of an unexposed portion with the stabilizer (D).

[0023] In the fourth place, the above objects and advantages of thepresent invention are attained by a refractive index pattern formingmethod comprising exposing a refractive index changing compositioncomprising (A) a decomposable compound, (B) a non-decomposable compoundhaving a lower refractive index than the decomposable compound (A) and(C) a radiation sensitive decomposer to radiation through a pattern maskand heating to decompose the decomposable polymer of an unexposedportion.

[0024] In the fifth place, the above objects and advantages of thepresent invention are attained by a refractive index pattern formed byany one of the above refractive index pattern forming methods.

[0025] In the sixth place, the above objects and advantages of thepresent invention are attained by an optical material formed by any oneof the above refractive index pattern forming methods.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0026]FIG. 1 is a schematic diagram of an apparatus for irradiatinglight to form a lens from the refractive index changing composition ofthe present invention; and

[0027]FIG. 2 is a schematic diagram of an apparatus for irradiatinglight to form a diffraction grating from the refractive index changingcomposition of the present invention.

[0028] In the present invention, the term “refractive index patterns”means a refractive index distribution type material consisting ofregions having different refractive indices.

[0029] A detailed description is subsequently given of each component ofa refractive index changing material used in the refractive indexpattern forming method of the present invention.

[0030] (A) Decomposable Compound

[0031] The decomposable compound (A) used in the present invention canbe an acid decomposable compound or a base decomposable compound and itsrefractive index is preferably 1.5 to 1.9. The weight average molecularweight of the decomposable compound (A) is preferably 100 to 500,000,more preferably 100 to 300,000.

[0032] The acid decomposable compound is selected from compounds havingat least one structure selected from the group consisting of structuresrepresented by the following formulas (1) to (8). These compounds may beused alone or in combination of two or more.

[0033] (In the formula (1), R¹ is an alkylene group,alkylene-arylene-alkylene group or arylene group, and R² is an alkylenegroup, alkylene-arylene-alkylene group, arylene group, alkylsilylenegroup or alkylgermylene group.)

[0034] (In the formula (2), M is Si or Ge, R³ is an alkylene group,alkylene-arylene-alkylene group, arylene group, alkylsilylene group oralkylgermylene group, R⁴ is an oxygen atom, alkylene group,alkylene-arylene-alkylene group, arylene group or single bond, R⁵, R⁶,R⁷ and R⁸ are each independently a hydrogen atom, alkyl group, arylgroup, alkoxy group or thioalkyl group, and m is an integer of 0 to 2.)

[0035] (In the formula (3), R⁹ and R¹⁰ are each independently analkylene group, alkylene-arylene-alkylene group, arylene group,alkylsilylene group or alkylgermylene group.)

[0036] (In the formula (4), R¹¹ is an oxyalkylene group or single bond,and R¹² is a hydrogen atom, alkyl group, alkylene-arylene-alkylene groupor aryl group.)

[0037] (In the formula (5), R¹³ is a hydrogen atom, alkyl group or arylgroup.)

[0038] (In the formula (6), R¹⁴ is an alkylene group or a structurerepresented by the following formula (6)-1, (6)-2 or (6)-3.)

[0039] (In the formula (6)-1, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are eachindependently a hydrogen atom, chain alkyl group having 1 to 6 carbonatoms, chlorine atom, bromine atom, iodine atom, hydroxyl group,mercapto group, carboxyl group, alkoxyl group having 1 to 6 carbonatoms, alkylthio group having 1 to 6 carbon atoms, haloalkyl grouphaving 1 to 6 carbon atoms, haloalkoxyl group having 1 to 6 carbonatoms, haloalkylthio group having 1 to 6 carbon atoms, hydroxyalkylgroup having 1 to 6 carbon atoms, mercaptoalkyl group having 1 to 6carbon atoms, hydroxyalkoxyl group having 1 to 6 carbon atoms,mercaptoalkylthio group having 1 to 6 carbon atoms, aryl group having 6to 10 carbon atoms or aralkyl group having 7 to 11 carbon atoms.)

—O—R¹⁹—O—  (6)-2

[0040] (In the formula (6)-2, R¹⁹ is an alkylene group.)

—NH—R²⁰—NH—  (6)-3

[0041] (In the formula (6)-3, R²⁰ is an alkylene group.)

[0042] (In the formula (7), R²¹ is an alkylene group,alkylene-arylene-alkylene group or arylene group.)

[0043] wherein, R²², R²³, R²⁴ and R²⁵ are each independently a hydrogenatom, chain alkyl group having 1 to 6 carbon atoms, chlorine atom,bromine atom, iodine atom, hydroxyl group, mercapto group, carboxylgroup, alkoxyl group having 1 to 6 carbon atoms, alkylthio group having1 to 6 carbon atoms, haloalkyl group having 1 to 6 carbon atoms,haloalkoxyl group having 1 to 6 carbon atoms, haloalkylthio group having1 to 6 carbon atoms, hydroxyalkyl group having 1 to 6 carbon atoms,mercaptoalkyl group having 1 to 6 carbon atoms, hydroxyalkoxyl grouphaving 1 to 6 carbon atoms, mercaptoalkylthio group having 1 to 6 carbonatoms, aryl group having 6 to 10 carbon atoms or aralkyl group having 7to 11 carbon atoms.

[0044] The base decomposable compound is selected from compounds havingat least one structure selected from the group consisting of structuresrepresented by the following formulas (9) to (12). These compounds maybe used alone or in combination of two or more.

[0045] (In the formula (9), R²⁶ is an alkylene group, aralkylene groupor arylene group, R²⁷ is an alkylene group, aralkylene group, arylenegroup, alkylene-arylene-alkylene group, alkylsilylene group oralkylgermylene group, R²⁸, R²⁹, R³⁰ and R³¹ are each independently ahydrogen atom, alkyl group, aryl group, alkoxyl group or thioalkylgroup, and i and j are each independently 0 or 1.)

[0046] (In the formula (10), R³² is an alkylene group, aralkylene groupor arylene group, and R³³ is an alkylene group, aralkylene group,arylene group, alkylene-arylene-alkylene group, alkylsilylene group oralkylgermylene group.)

[0047] (In the formula (11), R³⁴ and R³⁵ are each independently analkylene group, aralkylene group, arylene group,alkylene-arylene-alkylene group, alkylsilylene group or alkylgermylenegroup.)

[0048] (In the formula (12), R³⁶ and R³⁷ are each independently analkylene group, aralkylene group, arylene group,alkylene-arylene-alkylene group, alkylsilylene group or alkylgermylenegroup.)

[0049] All the above alkylene-arylene-alkylene groups each independentlyhave a structure represented by the following formula (13) or (14):

[0050] (In the formula (13), R³⁸, R³⁹, R⁴⁰ and R⁴¹ are eachindependently a hydrogen atom, chain alkyl group having 1 to 6 carbonatoms or aryl group having 6 to 10 carbon atoms, and R⁴², R⁴³, R⁴⁴ andR⁴⁵ are each independently a hydrogen atom, chlorine atom, bromine atom,hydroxyl group, mercapto group, alkoxy group, thioalkyl group,alkylester group, alkylthioester group, aryl group, cyano group or nitrogroup,)

[0051] (14), R⁴⁶, R⁴⁷, R⁴⁸ and R⁴⁹ are each independently a hydrogenatom, chain alkyl group having 1 to 6 carbon atoms or aryl group having6 to 10 carbon atoms, R⁵⁰, R⁵¹, R⁵², R⁵³, R⁵⁴, R⁵⁵, R⁵⁶ and R⁵⁷ are eachindependently a hydrogen atom, chlorine atom, bromine atom, hydroxylgroup, mercapto group, alkoxy group, thioalkyl group, alkylester group,alkylthioester group, aryl group, cyano group or nitro group, A¹ is —S—,—O—, —SO₂—, —CO—, —COO—, —OCOO—, —CH₂— or —C(R⁵⁸)₂—, and R⁵⁸ is a chainalkyl group having 1 to 6 carbon atoms.)

[0052] All the above arylene groups each independently have a structurerepresented by the following formula (15):

[0053] wherein R⁵⁹ to R⁶⁶ are each independently a hydrogen atom,chlorine atom, bromine atom, hydroxyl group, mercapto group, alkoxygroup, thioalkyl group, alkylester group, alkylthioester group, arylgroup, cyano group or nitro group, A² is —S—, —O—, —SO₂—, —CO—, —COO—,—OCOO—, —CH₂— or —C(R⁶⁷)₂—, and R⁶⁷ is a chain alkyl group having 1 to 6carbon atoms.

[0054] All the above alkylsilylene groups each independently have astructure represented by the following formula (16):

[0055] wherein R⁶⁸, R⁶⁹, R⁷⁰ and R⁷¹ are each independently a hydrogenatom, chain alkyl group having 1 to 6 carbon atoms or aryl group having6 to 10 carbon atoms, A³ is —O—, alkylene group or arylene group, and ais an integer of 0 or 1.

[0056] All the above alkylgermylene groups each independently have astructure represented by the following formula (17):

[0057] wherein R⁷², R⁷³, R⁷⁴ and R⁷⁵ are each independently a hydrogenatom, chain alkyl group having 1 to 6 carbon atoms or aryl group having6 to 10 carbon atoms, A⁴ is —O—, alkylene group or arylene group, and bis an integer of 0 or 1.

[0058] Preferably, the alkylene groups in the above formulas (16) and(17) are each independently a linear, branched or cyclic alkylene grouphaving 1 to 10 carbon atoms, such as methylene, 1,2-ethylene,1,3-trimethylene or 1,10-decamethylene, and the hydrogen atoms of theabove groups may be substituted by, for example, a chlorine atom,bromine atom, hydroxyl group, mercapto group, alkoxy group, thioalkylgroup, alkylester group, alkylthioester group, aryl group or cyanogroup.

[0059] Preferably, the alkyl groups of all the above alkyl groups,alkoxy groups, thioalkyl groups, alkylester groups and alkylthioestergroups are each independently a linear, branched or cyclic alkyl grouphaving 1 to 10 carbon atoms, and the hydrogen atoms of the above groupsmay be substituted by a chlorine atom, bromine atom, hydroxyl group,mercapto group, alkoxy group, thioalkyl group, alkylester group,alkylthioester group, aryl group or cyano group.

[0060] All the above aryl groups are each independently a phenyl group,naphthyl group, anthracenyl group or biphenyl group, and the hydrogenatoms of the above groups may be substituted by a chlorine atom, bromineatom, hydroxyl group, mercapto group, alkoxy group, thioalkyl group,alkylester group, alkylthioester group, cyano group or nitro group.

[0061] The chain alkyl group having 1 to 6 carbon atoms in the aboveformulas (6)-1 and (8) may be linear or branched, as exemplified bymethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl,n-pentyl, neopentyl, n-hexyl and thexyl.

[0062] The alkoxyl group having 1 to 6 carbon atoms maybe linear orbranched, as exemplified by methoxy, ethoxy, n-propoxy, i-propoxy,n-butoxy, i-butoxy, sec-butoxy, t-butoxy, n-pentyloxy, neopentyloxy,n-hexyloxy and thexyloxy.

[0063] The alkylthio group having 1 to 6 carbon atoms may be linear orbranched, as exemplified by methylthio, ethylthio, n-propylthio,i-propylthio, n-butylthio, i-butylthio, sec-butylthio, t-butylthio,n-pentylthio, neopentylthio, n-hexylthio and thexylthio.

[0064] Examples of the haloalkyl group having 1 to 6 carbon atomsinclude trifluoromethyl, pentafluoroethyl, heptafluoropropyl,chloromethyl, 2-chloroethyl, 3-chloropropyl, 1-chloromethylethyl,4-chlorobutyl, 2-chloromethylpropyl, 5-chloropentyl,3-chloromethylbutyl, 2-chloroethylpropyl, 6-chlorohexyl,3-chloromethylpentyl, 4-chloromethylpentyl, 2-chloroethylbutyl,bromomethyl, 2-bromoethyl, 3-bromopropyl, 1-bromomethylethyl,4-bromobutyl, 2-bromomethylpropyl, 5-bromopentyl, 3-bromomethylbutyl,2-bromoethylpropyl, 6-bromohexyl, 3-bromomethylpentyl,4-bromomethylpentyl and 2-bromoethylbutyl.

[0065] Examples of the haloalkoxyl group having 1 to 6 carbon atomsinclude trifluoromethoxy, pentafluoroethoxy, heptafluoropropoxy,chloromethoxy, 2-chloroethoxy, 3-chloropropoxy, 1-chloromethylethoxy,4-chlorobutoxy, 2-chloromethylpropoxy, 5-chloropentyloxy,3-chloromethylbutoxy, 2-chloroethylpropoxy, 6-chlorohexyloxy,3-chloromethylpentyloxy, 4-chloromethylpentyloxy, 2-chloroethylbutoxy,bromomethoxy, 2-bromoethoxy, 3-bromopropoxy, 1-bromomethylethoxy,4-bromobutoxy, 2-bromomethylpropoxy, 5-bromopentyloxy,3-bromomethylbutoxy, 2-bromoethylpropoxy, 6-bromohexyloxy,3-bromomethylpentyloxy, 4-bromomethylpentyloxy and 2-bromoethylbutoxy.

[0066] Examples of the haloalkylthio group having 1 to 6 carbon atomsinclude trifluoromethylthio, pentafluoroethylthio,heptafluoropropylthio, chloromethylthio, 2-chloroethylthio,3-chloropropylthio, 1-chloromethylethylthio, 4-chlorobutylthio,2-chloromethylpropylthio, 5-chloropentylthio, 3-chloromethylbutylthio,2-chloroethylpropylthio, 6-chlorohexylthio, 3-chloromethylpentylthio,4-chloromethylpentylthio, 2-chloroethylbutylthio, bromomethylthio,2-bromoethylthio, 3-bromopropylthio, 1-bromomethylethylthio,4-bromobutylthio, 2-bromomethylpropylthio, 5-bromopentylthio,3-bromomethylbutylthio, 2-bromoethylpropylthio, 6-bromohexylthio,3-bromomethylpentylthio, 4-bromomethylpentylthio and2-bromoethylbutylthio.

[0067] Examples of the hydroxyalkyl group having 1 to 6 carbon atomsinclude hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl,1-hydroxymethylethyl, 4-hydroxybutyl, 2-hydroxymethylpropyl,5-hydroxypentyl, 3-hydroxymethylbutyl, 2-hydroxyethylpropyl,6-hydroxyhexyl, 3-hydroxymethylpentyl, 4-hydroxymethylpentyl and2-hydroxyethylbutyl.

[0068] Examples of the mercaptoalkyl group having 1 to 6 carbon atomsinclude mercaptomethyl, 2-mercaptoethyl, 3-mercaptopropyl,1-mercaptomethylethyl, 4-mercaptobutyl, 2-mercaptomethylpropyl,5-mercaptopentyl, 3-mercaptomethylbutyl, 2-mercaptoethylpropyl,6-mercaptohexyl, 3-mercaptomethylpentyl, 4-mercaptomethylpentyl and2-mercaptoethylbutyl.

[0069] Examples of the hydroxyalkoxyl group having I to 6 carbon atomsinclude hydroxymethoxy, 2-hydroxyethoxy, 3-hydroxypropoxy,1-hydroxymethylethoxy, 4-hydroxybutoxy, 2-hydroxymethylpropoxy,5-hydroxypentyloxy, 3-hydroxymethylbutoxy, 2-hydroxyethylpropoxy,6-hydroxyhexyloxy, 3-hydroxymethylpentyloxy, 4-hydroxymethylpentyloxyand 2-hydroxyethylbutoxy.

[0070] Examples of the mercaptoalkylthio group having 1 to 6 carbonatoms include mercaptomethylthio, 2-mercaptoethylthio,3-mercaptopropylthio, 1-mercaptomethylethylthio, 4-mercaptobutylthio,2-mercaptomethylpropylthio, 5-mercaptopentylthio,3-mercaptomethylbutylthio, 2-mercaptoethylpropylthio,6-mercaptohexylthio, 3-mercaptomethylpentylthio,4-mercaptomethylpentylthio and 2-mercaptoethylbutylthio.

[0071] Examples of the aryl group having 6 to 10 carbon atoms includephenyl, tolyl, xylyl, cumenyl and 1-naphthyl.

[0072] Examples of the aralkyl group having 7 to 11 carbon atoms includebenzyl, α-methylbenzyl, phenethyl and naphthylmethyl.

[0073] Methods of producing acid decomposable compounds havingstructures represented by the above formulas (1) to (7) in the presentinvention as a recurring unit, for example, are already known.

[0074] Methods of producing a compound having a structure represented bythe above formula (1) are disclosed by Polymer Bull., 1. 199 (1978),JP-A 62-136638, EP 225,454, U.S. Ser. No. 806,597, JP-A 4-303843, JP-A7-56354 and the like.

[0075] Methods of producing a compound having a structure represented bythe above formula (2) are disclosed by Macromolecules 29, 5529 (1996),Polymer 17, 1086 (1976), JP-A 60-37549 and the like.

[0076] Methods of producing a compound having a structure represented bythe above formula (3) are disclosed by Electrochem. Soc., Solid StateSci. Technol., 133(1) 181 (1986), J. Imaging Sci., 30(2)59 (1986),Macromol. Chem., Rapid Commun., 7, 121(1986) and the like.

[0077] Methods of producing a compound having a structure represented bythe above formula (4) are disclosed by USP 3,894,253, JP-A 62-190211,JP-A 2-146544, Macromol. Chem., 23, 16(1957), JP-A63-97945, PolymerSci.,A-1, 8, 2375(1970), U.S. Pat. No. 4,247,611, EP 41,657, JP-A 57-31674,JP-A 64-3647, JP-A 56-17345 and the like.

[0078] Methods of producing a compound having a structure represented bythe above formula (5) are disclosed by Prepr. Eur. Disc Meet. PolymerSci., Strasbourg, p.106 (1978), Macromol. Chem., 179, 1689 (1978) andthe like.

[0079] Methods of producing a compound having a structure represented bythe above formula (6) are disclosed by U.S. Pat. Nos. 3,894,253,3,940,507, JP-A 62-190211 and the like.

[0080] Methods of producing a compound having a structure represented bythe above formula (7) are disclosed by J. Am. Chem. Soc., 54, 1579(1932), J. Polym. Sci., 29, 343 (1958), J. Polym. Sci., Part A, Polym.Chem., 25, 3373 (1958), Macromolecules, 25, 12, (1992), Macromolecules,20, 705, (1997), Macromolecules, 21, 1925, (1998), Macromol. Chem.,Rapid Commun., 11, 83 (1990) and the like.

[0081] A compound having a structure represented by the above formula(8) can be produced by cationically or anionically polymerizing acompound represented by the following formula (8)-1 in a solvent in thepresence of a molecular weight modifier as required:

[0082] wherein R²⁰¹, R²⁰², R²⁰³ and R²⁰⁴ are each independently a groupselected from groups represented by R²², R²³, R²⁴ and R²⁵ in the formula(8).

[0083] The compound represented by the above formula (8) may be acopolymer of one or more compounds selected from the group consisting ofa compound represented by the following formula (8)-2, a compoundrepresented by the following formula (8)-3 and a monomer other thanthese and a compound represented by the above formula (8)-1. In thiscase, the total amount of the one or more compounds selected from thegroup consisting of a compound represented by the following formula(8)-2, a compound represented by the following formula (8)-3 and amonomer other than these may be 100 parts or less by weight based on 100parts by weight of the compound represented by the above formula (8)-1:

[0084] wherein R²⁰⁵ is a hydrogen atom or alkyl group having 1 to 10carbon atoms, and R²⁰⁶, R²⁰⁷, R²⁰⁸, R²⁰⁹ and R²¹⁰ are each independentlya hydrogen atom, chain alkyl group having 1 to 6 carbon atoms, chlorineatom, bromine atom, iodine atom, hydroxyl group, mercapto group,carboxyl group, alkoxyl group having 1 to 6 carbon atoms, alkylthiogroup having 1 to 6 carbon atoms, haloalkyl group having 1 to 6 carbonatoms, haloalkoxyl group having 1 to 6 carbon atoms, haloalkylthio grouphaving 1 to 6 carbon atoms, hydroxyalkyl group having 1 to 6 carbonatoms, mercaptoalkyl group having 1 to 6 carbon atoms, hydroxyalkoxylgroup having 1 to 6 carbon atoms, mercaptoalkylthio group having 1 to 6carbon atoms, aryl group having 6 to 10 carbon atoms, aralkyl grouphaving 7 to 11 carbon atoms, or two out of R²⁰⁶, R²⁰⁷, R²⁰⁸, R²⁰⁹ andR²¹⁰ may be bonded together to form a 4- to 7-membered ring togetherwith carbon atoms bonded thereto,

[0085] wherein R²¹¹ and R²¹² are each independently a hydrogen atom,alkyl group having 1 to 10 carbon atoms, haloalkyl group having 1 to 10carbon atoms, hydroxyalkyl group having 1 to 10 carbon atoms,mercaptoalkyl group having 1 to 10 carbon atoms, aryl group having 6 to10 carbon atoms, aralkyl group having 7 to 11 carbon atoms,(polyethylene glycol)ethyl group having 1 to 5 ethyleneoxy recurringunits, (polypropylene glycol) propyl group having 1 to 5 propyleneoxyrecurring units, (polyethylene sulfide)ethyl group having 1 to 5recurring units or (polypropylene sulfide)propyl group having 1 to 5recurring units.

[0086] Examples of the monomer other than these include compounds havingtwo aldehyde groups in one molecule such as glyoxal, succinaldehyde,glutaraldehyde, malealdehyde, 1,8-octanedialdehyde, m-phthalaldehyde,p-phthalaldehyde, 2,3-naphthalenedicarboxyaldehyde,2,3-anthracenedicarboxyaldehyde, 9,10-anthracenedicarboxyaldehyde,4,4′-bisbenzaldehyde, 2,5-dimethoxy-1,4-dicarboxyaldehyde,2,2′-(ethylenedioxy)dibenzaldehyde, 2,2′-biphenyldicarboxyaldehyde,bis(2-formylphenyl)ether and6,6′-dihydroxy-5,5′-dimethoxy-[1,1′-biphenyl]-3,3′-dicarboxyaldehyde;and compounds having three or more aldehyde groups in one molecule suchas salicylaldehydechromium complex, aluminumformylacetate,(1,1′,3′,1″)-terphenyl-2,6,2″,6″-tetracarbaldehyde,2-hydroxybenzene-1,3,5-tricarbaldehyde and1,2,4,5-tetra(p-formylphenyl)benzene.

[0087] Compounds obtained by substituting the hydrogen atoms of theabove compounds by an alkoxyl group having 1 to 10 carbon atoms,haloalkyl group having 1 to 10 carbon atoms, haloalkoxyl group having 1to 10 carbon atoms, haloalkylthio group having 1 to 10 carbon atoms,hydroxyalkyl group having 1 to 10 carbon atoms, mercaptoalkyl grouphaving 1 to 10 carbon atoms, hydroxyalkoxyl group having 1 to 10 carbonatoms, mercaptoalkylthio group having 1 to 10 carbon atoms, aryl grouphaving 6 to 10 carbon atoms, aralkyl group having 7 to 11 carbon atoms,(polyethylene glycol)ethyl group having 1 to 5 recurring units or(polypropylene glycol)propyl group having 1 to 5 recurring units mayalso be used.

[0088] Cationic polymerization and/or anionic polymerization for theproduction of the compound having a structure represented by the aboveformula (8) may be carried out in the presence of an anionicpolymerization catalyst, coordination anionic polymerization catalyst orcationic polymerization catalyst. Typical examples of the anionicpolymerization catalyst or the coordination anionic polymerizationcatalyst include alkali metals such as sodium and lithium; alkyl metalcompounds such as s-butyl lithium; alkali metal complex compounds suchas sodium/naphthalene; alkali metal alkoxides such as sodium methoxide;amines such as n-butylamine and diethylamine; quaternary ammonium saltssuch as ammonium stearate and tetrabutylammonium acetate; andtetravalent organic tin compounds such as dibutyltin dilaurate,tributyltin chloride and diethyltin dilaurate.

[0089] Typical examples of the cationic polymerization catalyst includetin tetrachloride, tin tetrabromide, titanium tetrachloride, aluminumtrichloride, zinc chloride, boron trifluoride, boron trifluoride-diethyletherate, perchloric acid, acetyl perchlorate, p-toluenesulfonic acid,triethyloxonium tetrafluoroborate, triethyl aluminum and diethylaluminumchloride.

[0090] Examples of the polymerization solvent include aliphatichydrocarbons such as hexane, heptane and cyclohexane; aromatichydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbonhalides such as methylene chloride, ethylene chloride and carbontetrachloride; and aromatic hydrocarbon halides such as chlorobenzeneand orthodichlorobenzene. These organic solvents may be used alone or inadmixture of two or more. The organic solvent is preferably dehydratedand purified to the full.

[0091] The molecular weight modifier which is optionally coexistent inthe production of this polymer is preferably dissolved or dispersed in areaction system uniformly and an alcohol or a carboxylic acid may beused as the molecular weight modifier.

[0092] Examples of the alcohol include methyl alcohol, ethyl alcohol,hexyl alcohol, cyclohexyl alcohol and benzyl alcohol. Examples of thecarboxylic acid include formic acid, acetic acid, propionic acid, lauricacid, palmitic acid and benzoic acid. The amount of the molecular weightmodifier is suitably adjusted according to the molecular weight of apolymer of interest and can be easily determined experimentally.

[0093] The reaction temperature is preferably set to a range of −200 to50° C. However, in consideration of the freezing point and boiling pointof the organic solvent, it is more preferably set to a range of −100 to30° C. in most cases. The reaction time is not particularly limited butcan be suitably set to a range of 100 hours or less. After the passageof a predetermined polymerization time, for example, the obtainedreaction mixture is filtered and the obtained solid is washed with ionexchange water and vacuum dried to produce the compound having astructure represented by the above formula (8) of interest. Since thehydroxyl group at a terminal of a hemiacetal type molecule formed by theabove polymerization reaction slightly lacks thermal stability, it iscapped at the terminal of molecule in accordance with a method known asmeans of capping a polyacetal-based polymer, such as esterification,etherification or urethanation as required, to improve its stability.

[0094] Methods of producing base decomposable compounds havingstructures represented by the above formulas (9) to (12) as recurringunits are also known.

[0095] Methods of producing a compound having a structure represented bythe above formula (9) are disclosed by Macromol. Chem., Rapid Commun.,5, 151 (1984), Macromol. Chem., 189, 2229 (1988), Macromol. Chem., 187,2525 (1986), Polym. J., 22, 803 (1990) and the like.

[0096] Methods of producing a compound having a structure represented bythe above formula (10) are disclosed by J. Polym. Sci., 47, 1523 (1993),J. Appl. Polym. Sci., 35, 85 (1985), J. Polym. Sci., Polym. Chem. Ed.,22, 1579 (1984), J. Polym. Sci., Polym. Chem. Ed., 14, 655 (1976), J.Polym. Sci., Polym. Chem. Ed., 17, 2429 (1979) and the like.

[0097] Methods of producing a compound having a structure represented bythe above formula (11) are disclosed by J. Macromol. Sci. -Chem., A9,1265 (1975) and the like.

[0098] Methods of producing a compound having a structure represented bythe above formula (12) are disclosed by Polym. Bull., 14, 85 (1985),Macromol. Chem., 189, 1323 (1988) and the like.

[0099] (B) Non-decomposable Compound

[0100] The non-decomposable compound (B) used in the present inventionis stable to an acid or base and preferably has high opticaltransparency. The refractive index of the component (B) can be suitablyset and adjusted to a preferred value according to application purpose.The refractive index n_(B) of the compound (B) is smaller than therefractive index n_(A) of the polymer A and particularly preferablysatisfies the following expression (1).

n_(A)−n_(B)≧0.05  (1)

[0101] The non-decomposable compound (B) may be a non-decomposablepolymer.

[0102] Examples of the non-decomposable polymer (B) include anacrylic-based resin, urethane-based resin, polyester-based resin,polycarbonate-based resin, norbornene-based resin, styrene-based resin,polyether sulfone-based resin, silicon resin, polyamide resin, polyimideresin, polysiloxane-based resin, fluorinated resin, polybutadiene-basedresin, vinylether-based resin and vinylester-based resin. A preferrednon-decomposable polymer (B) can be suitably selected according to therefractive index of the decomposable polymer (A) used. To increase thedifference between the refractive index of the decomposable polymer (A)and the refractive index of the non-decomposable polymer (B) and toreduce a transmission loss though the optical path is long, anon-decomposable polymer (B) having a fluorine atom substituted f or thehydrogen atom of the above resin may be advantageously used.

[0103] Illustrative examples of the non-decomposable polymer (B) includethe following polymers (the figures within parentheses are refractiveindex values measured by d-ray): polyvinylidene fluoride (1.42),polydimethylsiloxane (1.43), polytrifluoroethyl methacrylate (1.44),polyoxypropylene (1.45), polyvinylisobutyl ether (1.45), polyvinylethylether (1.45), polyoxyethylene (1.46), polyvinylbutyl ether (1.46),polyvinylpentyl ether (1.46), polyvinylhexyl ether (1.46),poly(4-methyl-1-pentene) (1.46 to 1.47), cellulose acetate butyrate(1.46 to 1.49), poly( 4-fluoro-2-trifluoromethylstyrene) (1.46),polyvinyloctyl ether (1.46), poly(vinyl 2-ethylhexyl ether) (1.46),polyvinyldecyl ether (1.46), poly( 2-methoxyethyl acrylate) (1.46),polybutyl acrylate (1.46), polybutyl acrylate (1.47), poly(t-butylmethacrylate) (1.46), polyvinyldodecyl ether (1.46), poly(3-ethoxypropylacrylate) (1.47), polyoxycarbonyl tetramethylene (1.47), polyvinylpropionate (1.47), polyvinyl acetate (1.47), polyvinylmethyl ether(1.47), polyethyl acrylate (1.47), ethylene-vinyl acetate copolymer(1.47 to 1.50), (80% to 20% of vinylacetate)cellulose propionate (1.47to 1.49), cellulose acetate propionate (1.47), benzyl cellulose (1.47 to1.58), phenol-formaldehyde resin (1.47 to 1.70), cellulose triacetate(1.47 to 1.48), polyvinylmethyl ether (isotactic) (1.47),poly(3-methoxypropyl acrylate) (1.47), poly(2-ethoxyethyl acrylate)(1.47), polymethyl acrylate (1.47 to 1.48), polyisopropyl methacrylate(1.47), poly(1-decene) (1.47), polypropylene (atactic, density of0.8575g/cm³) (1.47), poly(vinyl sec-butyl ether) (isotactic) (1.47),polydodecyl methacrylate (1.47), polyoxyethylene oxysuccinoyl (1.47),(polyethylene succinate) polytetradecyl methacrylate (1.47),ethylene-propylene copolymer (EPR-rubber) (1.47to 1.48), polyhexadecylmethacrylate (1.48), polyvinyl formate (1.48), poly(2-fluoroethylmethacrylate) (1.48), polyisobutyl methacrylate (1.48), ethyl cellulose(1.48), polyvinyl acetal (1.48 to 1.50), cellulose acetate (1.48 to1.50), cellulose tripropionate (1.48 to 1.49), polyoxymethylene (1.48),polyvinyl butyral (1.48 to 1.49), poly(n-hexyl methacrylate) (1.48),poly(n-butyl methacrylate) (1.48), polyethylidene dimethacrylate (1.48),poly(2-ethoxyethyl methacrylate) (1.48), polyoxyethylene oxymaleoyl(1.48), (polyethylene maleate) poly(n-propyl methacrylate) (1.48),poly(3,3,5-trimethylcyclohexyl methacrylate) (1.49), polyethylmethacrylate (1.49), poly(2-nitro-2-methylpropyl methacrylate) (1.49),polytriethylcarbinyl methacrylate (1.49), poly(1,1-diethylpropylmethacrylate) (1.49), polymethylmethacrylate (1.49),poly(2-decyl-1,3-butadiene) (1.49), polyvinyl alcohol (1.49 to 1.53),polyethyl glycolate methacrylate (1.49), poly(3-methylcyclohexylmethacrylate) (1.49), poly(cyclohexyl α-ethoxyacrylate) (1.50), methylcellulose (low viscosity) (1.50), poly(4-methylcyclohexyl methacrylate)(1.50), polydecamethylene glycol dimethacrylate (1.50), polyurethane(1.50 to 1.60), poly(1,2-butadiene) (1.50), polyvinyl formal (1.50),poly(2-bromo-4-trifluoromethylstyrene) (1.50), cellulose nitrate (1.50to 1.51), poly(sec-butyl α-chloroacrylate) (1.50),poly(2-heptyl-1,3-butadiene) (1.50), poly(ethyl α-chloroacrylate)(1.50), poly(2-isopropyl-1,3-butadiene) (1.50), poly(2-methylcyclohexylmethacrylate) (1.50), polypropylene (density of 0.9075 g/cm³)(1.50),polyisobutene (1.51), polybornyl methacrylate (1.51),poly(2-t-butyl-1,3-butadiene) (1.51), polyethylene glycol dimethacrylate(1.51), polycyclohexyl methacrylate (1.51),poly(cyclohexanediol-1,4-dimethacrylate) (1.51), butyl rubber(unvulcanized) (1.51), polytetrahydrofurfuryl methacrylate) (1.51),guttapercha (β) (1.51), polyethylene ionomer (1.51), polyoxyethylene(high molecular weight) (1.51 to 1.54), polyethylene (density of 0.914g/cm³) (1.51), (density of 0.94 to 0.945 g/cm³) (1.52 to 1.53), (densityof 0.965 g/cm³) (1.55), poly(1-methylcyclohexyl methacrylate) (1.51),poly(2-hydroxyethylmethacrylate) (1.51), polyvinyl chloroacetate (1.51),polybutene (isotactic) (1.51), polyvinylmethacrylate (1.51),poly(N-butyl-methacrylamide) (1.51), guttapercha (α) (1.51), terpeneresin (1.52), poly(1,3-butadiene) (1.52), shellac (1.51 to 1.53),poly(methyl α-chloroacrylate) (1.52), poly(2-chloroethyl methacrylate)(1.52), poly(2-diethylaminoethyl methacrylate) (1.52), poly(2-chlorocyclohexylmethacrylate) (1.52), poly(1,3-butadiene) (35% ofcis-form; 56% of trans-form 1.5180; 7% of 1,2-bond-form), natural rubber(1.52), polyallyl methacrylate (1.52), polyvinyl chloride +40% ofdioctyl phthalate (1.52), polyacrylonitrile (1.52),polymethacrylonitrile (1.52), poly(1,3-butadiene) (rich with cis type)(1.52), butadiene-acrylonitrile copolymer (1.52), polymethyl isopropenylketone (1.52), polyisoprene (1.52), polyester resin rigid (about 50% ofstyrene) (1.52 to 1.54), poly(N-(2-methoxyethyl)methacrylamide) (1.52),poly(2,3-dimethylbutadiene) (methyl rubber) (1.53), vinyl chloride-vinylacetate copolymer (95/5 to 90/10) (1.53 to 1.54), polyacrylic acid(1.53), poly(1,3-dichloropropyl methacrylate) (1.53),poly(2-chloro-1-(chloromethyl)ethyl methacrylate) (1.53), polyacrolein(1.53), poly(1-vinyl-2-pyrrolidone) (1.53), rubber hydrochloride (1.53to1.55), nylon 6; nylon 6,6; nylon 6,10 (molded product) (1.53),butadiene-styrene copolymer (about 30% of styrene) (1.53),poly(cyclohexyl-α-chloroacrylate) block copolymer (1.53),poly(2-chloroethyl-α-chloroacrylate) (1.53), butadiene-styrene copolymer(about 75/25) (1.54), poly(2-aminoethyl methacrylate) (1.54),polyfurfuryl methacrylate (1.54), polybutylmercaptylmethacrylate (1.54),poly(1-phenyl-n-amyl methacrylate) (1.54), poly(N-methyl-methacrylamide)(1.54), cellulose (1.54), polyvinyl chloride (1.54 to 1.55), ureaformaldehyde resin (1.54 to 1.56), poly(sec-butyl α-bromoacrylate)(1.54), poly(cyclohexyl α-bromoacrylate) (1.54), poly(2-bromoethylmethacrylate) (1.54), polydihydroabietic acid (1.54), polyabietic acid(1.546), polyethylmercaptyl methacrylate (1.55),poly(N-allylmethacrylamide) (1.55), poly(1-phenylethyl methacrylate)(1.55), polyvinylfuran (1.55), poly(2-vinyltetrahydrofuran) (1.55),poly(vinylchloride)+40% of tricresyl phosphate (1.55),poly(p-methoxybenzyl methacrylate) (1.55), polyisopropyl methacrylate)(1.55), poly(p-isopropylstyrene) (1.55), polychloroprene (1.55 to 1.56),poly(oxyethylene-α-benzoate-ω-methacrylate) (1.56), poly(p,p′-xylylenyldimethacrylate) (1.56), poly(1-phenylallyl methacrylate) (1.56),poly(p-cyclohexylphenyl methacrylate) (1.56), poly(2-phenylethylmethacrylate) (1.56), poly(oxycarbonyloxy-1,4-phenylene-1-propyl)(1.56), poly(1-(o-chlorophenyl)ethyl methacrylate) (1.56),styrene-maleic anhydride copolymer (1.56), poly(1-phenylcyclohexylmethacrylate) (1.56),poly(oxycarbonyloxy-1,4-phenylene-1,3-dimethyl-butylidene-1,4-phenylene)(1.57), poly(methyl α-bromoacrylate) (1.57), polybenzyl methacrylate(1.57), poly(2-(phenylsulfonyl)ethyl methacrylate) (1.57), poly(m-cresylmethacrylate) (1.57), styrene-acrylonitrile copolymer (about 75/25)(1.57), poly(oxycarbonyloxy-1,4-phenylene isobutylidene-1,4-phenylene)(1.57), poly(o-methoxyphenyl methacrylate) (1.57), polyphenylmethacrylate (1.57), poly(o-cresyl methacrylate) (1.57), polydiallylphthalate (1.57), poly(2,3-dibromopropyl methacrylate) (1.57),poly(oxycarbonyloxy-1,4-phenylene-1-methyl-butylidene-1, 4-phenylene)(1.57), poly(oxy-2,6-dimethylphenylene) (1.58), polyoxyethyleneoxyterephthaloyl (amorphous) (1.58), polyethylene terephthalate (1.51 to1.64), polyvinyl benzoate (1.58),poly(oxycarbonyloxy-1,4-phenylenebutylidene-1,4-phenylene) (1.58),poly(1,2-diphenylethyl methacrylate) (1.58), poly(o-chlorobenzylmethacrylate) (1.58), 25poly(oxycarbonyloxy-1,4-phenylene-sec-butylidene-1,4-phenylene) (1.58),polyoxypentaerythritoloxyphthaloyl (1.58), poly(m-nitrobenzylmethacrylate) (1.58),poly(oxycarbonyloxy-1,4-phenyleneisopropylidene-1,4-phenylene) (1.59),poly(N-(2-phenylethyl)methacrylamide) (1.59),poly(4-methoxy-2-methylstyrene) (1.59), poly(o-methylstyrene) (1.59),polystyrene (1.59),poly(oxycarbonyloxy-1,4-phenylenecyclohexylidene-1,4-phenylene) (1.59),poly(o-methoxystyrene) (1.59), polydiphenylmethyl methacrylate (1.59),poly(oxycarbonyloxy-1,4-phenyleneethylidene-1,4-phenylene) (1.59),poly(p-bromophenyl methacrylate) (1.60), poly(N-benzylmethacrylamide)(1.60), poly(p-methoxystyrene) (1.60), polyvinylidene chloride (1.60 to1.63), polysulfide (“Thiokol”) (1.6 to 1.7), poly(o-chlorodiphenylmethylmethacrylate) (1.60),poly(oxycarbonyloxy-1,4-(2,6-dichloro)phenylene-isopropylidene-1,4-(2,6-dichloro)phenylene)(1.61), poly(oxycarbonyloxybis(1,4-(3,5-dichlorophenylene)))polypentachlorophenyl methacrylate (1.61), poly(o-chlorostyrene) (1.61),poly(phenyl α-bromoacrylate) (1.61), poly(p-divinylbenzene) (1.62),poly(N-vinylphthalimide) (1.62), poly(2,6-dichlorostyrene) (1.62),poly(β-naphthyl methacrylate) (1.63), poly(α-naphthylcarbinylmethacrylate) (1.63), polysulfone (1.63), poly(2-vinylthiophene) (1.64),poly(α-naphthyl methacrylate) (1.64),poly(oxycarbonyloxy-1,4-phenylenediphenyl-methylene-1,4-phenylene)(1.65), polyvinylphenyl sulfide (1.66), butylphenol formaldehyde resin(1.66), urea-thiourea-formaldehyde resin (1.66), polyvinyl naphthalene(1.68), polyvinyl carbazole (1.68), naphthalene-formaldehyde resin(1.70), phenol-formaldehyde resin (1.70), polypentabromophenylmethacrylate (1.71) and the like.

[0104] Out of these, compounds having a d-ray refractive index of 1.6 orless are preferred and compounds having a d-ray refractive index of 1.5or less are more preferred.

[0105] The weight average molecular weight of the non-decomposablecompound (B) is preferably 100 to 500,000, more preferably 100 to200,000.

[0106] A compound represented by the following formula (18), hydrolysateor condensate thereof is also used as the non-decomposable compound (B):

R²¹³ _(n)Si(OR²¹⁴)_(4−n)  (18)

[0107] wherein R²¹³ and R²¹⁴ may be the same or different and each amonovalent organic group, and n is an integer of 0 to 2.

[0108] Examples of the monovalent organic group in the above formula(18) include alkyl group, aryl group, allyl group and glycidyl group.Examples of the alkyl group include methyl, ethyl, propyl and butyl, outof which an alkyl group having 1 to 5 carbon atoms is preferred. Thealkyl group maybe linear or branched and may contain a halogen atom suchas fluorine atom substituted for a hydrogen atom. Examples of the arylgroup in the above formula (18) include phenyl and naphthyl. n ispreferably 1 or 2 in the above formula (18).

[0109] Illustrative examples of the alkylalkoxysilane represented by theabove formula (18) include methyl trimethoxysilane, methyltriethoxysilane, methyl tri-n-propoxysilane, methyl triisopropoxysilane,methyl tri-n-butoxysilane, methyl tri-sec-butoxysilane, methyltri-tert-butoxysilane, methyl triphenoxysilane, ethyl trimethoxysilane,ethyl triethoxysilane, ethyl tri-n-propoxysilane, ethyltruisopropoxysilane, ethyl tri-n-butoxysilane, ethyltri-sec-butoxysilane, ethyl tri-tert-butoxysilane, ethyltriphenoxysilane, n-propyl trimethoxysilane, n-propyl triethoxysilane,n-propyl tri-n-propoxysilane, n-propyl triisopropoxysilane, n-propyltri-n-butoxysilane, n-propyltri-sec-butoxysilane, n-propyltri-tert-butoxysilane, n-propyl triphenoxysilane, isopropyltrimethoxysilane, isopropyl triethoxysilane, isopropyltri-n-propoxysilane, isopropyl triisopropoxysilane, isopropyltri-n-butoxysilane, isopropyl tri-sec-butoxysilane, isopropyltri-tert-butoxysilane, isopropyl triphenoxysilane, n-butyltrimethoxysilane, n-butyl triethoxysilane, n-butyl tri-n-propoxysilane,n-butyl triisopropoxysilane, n-butyl tri-n-butoxysilane,n-butyltri-sec-butoxysilane,n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, sec-butyl trimethoxysilane, sec-butylisotriethoxysilane, sec-butyl tri-n-propoxysilane,sec-butyltruisopropoxysilane, sec-butyltri-n-butoxysilane, sec-butyltri-sec-butoxysilane, sec-butyl tri-tert-butoxysilane, sec-butyltriphenoxysilane, tert-butyl trimethoxysilane, tert-butyltriethoxysilane, tert-butyl tri-n-propoxysilane, tert-butyltruisopropoxysilane, tert-butyl tri-n-butoxysilane, tert-butyltri-sec-butoxysilane, tert-butyl tri-tert-bu, tert-butyltriphenoxysilane, cyclohexyl trimethoxysilane, cyclohexyltriethoxysilane, cyclohexyl tri-n-propoxysilane, cyclohexyltruisopropoxysilane, cyclohexyl tri-n-butoxysilane, cyclohexyltri-sec-butoxysilane, cyclohexyl tri-tert-butoxysilane, cysilane,cyclohexyl triphenoxysilane, norbornyl trimethoxysilane, norbornyltriethoxysilane, norbornyl tri-n-propoxysilane, norbornyltriisopropoxysilane, norbornyl tri-n-butoxysilane, norbornyltri-sec-butoxysilane, norbornyl tri-tert-butoxysilane, norbornyltriphenoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane,phenyl tri-n-propoxysilane, phenyl triisopropoxysilane, phenyltri-n-butoxysilane, phenyl tri-sec-butoxysilane, phenyltri-tert-butoxysilane, phenyl triphenoxysilane, dimethyldimethoxysilane, dimethyl diethoxysilane, dimethyl di-n-propoxysilane,dimethyl diisopropoxysilane, dimethyl di-n-butoxysilane, dimethyldi-sec-butoxysilane, dimethyl di-tert-butoxysilane, dimethyldiphenoxysilane, diethyl dimethoxysilane, diethyl diethoxysilane,diethyl di-n-propoxysilane, diethyl diisopropoxysilane, diethyldi-n-butoxysilane, diethyl di-sec-butoxysilane, diethyldi-tert-butoxysilane, diethyl diphenoxysilane, di-n-propyldimethoxysilane, di-n-propyl diethoxysilane, di-n-propyldi-n-propoxysilane, di-n-propyl diisopropoxysilane, di-n-propyldi-n-butoxysilane, di-n-propyl di-sec-butoxysilane, di-n-propyldi-tert-butoxysilane, di-n-propyl diphenoxysilane, diisopropyldimethoxysilane, diisopropyl diethoxysilane, diisopropyldi-n-propoxysilane, diisopropyl diisopropoxysilane, diisopropyldi-n-butoxysilane, diisopropyl di-sec-butoxysilane, diisopropyldi-tert-butoxysilane, diisopropyl diphenoxysilane, di-n-butyldimethoxysilane, di-n-butyl diethoxysilane, di-n-butyldi-n-propoxysilane, di-n-butyl diisopropoxysilane, di-n-butyldi-n-butoxysilane, di-n-butyl di-sec-butoxysilane, di-n-butyldi-tert-butoxysilane, di-n-butyl diphenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyl diethoxysilane, di-sec-butyldi-n-propoxysilane, di-sec-butyl diisopropoxysilane, di-sec-butyldi-n-butoxysilane, di-sec-butyl di-sec-butoxysilane, di-sec-butyldi-tert-butoxysilane, di-sec-butyl diphenoxysilane, di-tert-butyldimethoxysilane, di-tert-butyl diethoxysilane, di-tert-butyldi-n-propoxysilane, di-tert-butyl diisopropoxysilane, di-tert-butyldi-n-butoxysilane, di-tert-butyl di-sec-butoxysilane, di-tert-butyldi-tert-butoxysilane, di-tert-butyl diphenoxysilane, di-tert-butyldimethoxysilane, dicyclohexyl diethoxysilane, di-tert-butyldi-n-propoxysilane, dicyclohexyl diisopropoxysilane, dicyclohexyldi-n-butoxysilane, dicyclohexyl di-sec-butoxysilane, dicyclohexyldi-tert-butoxysilane, dicyclohexyl diphenoxysilane, di-tert-butyldimethoxysilane, dinorbornyl diethoxysilane, di-tert-butyldi-n-propoxysilane, dinorbornyl diisopropoxysilane, dinorbornyldi-n-butoxysilane, dinorbornyl di-sec-butoxysilane, dinorbornyldi-tert-butoxysilane, dinorbornyl diphenoxysilane, diphenyldimethoxysilane, diphenyl diethoxysilane, diphenyl di-n-propoxysilane,diphenyl diisopropoxysilane, diphenyl di-n-butoxysilane, diphenyldi-sec-butoxysilane, diphenyl di-tert-butoxysilane, diphenyldiphenoxysilane, divinyl trimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyl triethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyl triethoxysilane, γ-trifluoropropyltrimethoxysilane and γ-trifluoropropyl triethoxysilane. Compoundscontaining fluorine atoms substituted for some or all of the hydrogenatoms of the above compounds may also be used. These alkylalkoxysilanesmay be used alone or in combination of two or more.

[0110] Out of the compounds represented by the above formula (18),alkyltrialkoxysilanes of the formula (18) in which n is 1 areparticularly preferred. Out of these, methyl trimethoxysilane and methyltriethoxysilane are preferred. When methyl trimethoxysilane and/ormethyl triethoxysilane are/is used in an amount of 70 mol % or morebased on the total of all the alkylalkoxysilanes, a cured product havinggood balance between heat resistance and refractive index is obtained. Ahydrolysate and condensate of a compound represented by the aboveformula (18) are more preferred than the compound represented by theabove formula (18). When the component (B) is a condensate of a compoundrepresented by the above formula (18), it preferably has a weightaverage molecular weight of 500 to 100,000 in terms of polystyrene.

[0111] When a hydrolysate and/or condensate of a compound represented bythe above formula (18) are/is used as the component (B), a hydrolyticreaction and/or a condensation reaction are/is carried out in thepresence of water and a suitable catalyst as will be describedhereinbelow.

[0112] Stated more specifically, the compound represented by the aboveformula (18) is dissolved in a suitable organic solvent and water isintermittently or continuously added to this solution. The catalyst maybe dissolved or dispersed in the organic solvent in advance, ordissolved or dispersed in water to be added.

[0113] The temperature for carrying out the hydrolytic reaction and/orcondensation reaction is generally 0 to 100° C., preferably 15 to 80° C.

[0114] Water for carrying out the hydrolysis and/or condensation of thecompound represented by the above formula (18) is not particularlylimited but preferably ion exchange water.

[0115] The amount of water is preferably 0.25 to 3 mols, particularlypreferably 0.3 to 2.5 mols based on 1 mol of the total of groupsrepresented by R²¹⁴O— of the compound represented by the above formula(18).

[0116] The catalyst for carrying out the hydrolysis and/or condensationof the compound represented by the above formula (18) is a metal chelatecompound, organic acid, inorganic acid, organic base or inorganic base.

[0117] Illustrative examples of the metal chelate compound used as acatalyst include titanium chelate compounds such astriethoxy•mono(acetylacetonato)titanium,tri-n-propoxy•mono(acetylacetonato)titanium,tri-i-propoxy•mono(acetylacetonato)titanium,tri-n-butoxy•mono(acetylacetonato)titanium, tri-sec-butoxy•mono(acetylacetonato)titanium, tri-t-butoxy•mono(acetylacetonato)titanium,diethoxy•bis (acetylacetonato)titanium,di-n-propoxy•bis(acetylacetonato)titanium,di-i-propoxy•bis(acetylacetonato)titanium,di-n-butoxy•bis(acetylacetonato)titanium,di-sec-butoxy•bis(acetylacetonato)titanium,di-t-butoxy•bis(acetylacetonato)titanium,monoethoxy•tris(acetylacetonato)titanium,mono-n-propoxy•tris(acetylacetonato)titanium,mono-i-propoxy•tris(acetylacetonato)titanium,mono-n-butoxy•tris(•acetylacetonato)titanium,mono-sec-butoxy•tris(acetylacetonato)titanium,mono-t-butoxy•tris(acetylacetonato)titanium,tetrakis(acetylacetonato)titanium,triethoxy•mono(ethylacetoacetate)titanium,tri-n-propoxy•mono(ethylacetoacetate)titanium,tri-i-propoxy•mono(ethylacetoacetate)titanium,tri-n-butoxy•mono(ethylacetoacetate)titanium,tri-sec-butoxy•mono(ethylacetoacetate)titanium,tri-t-butoxy•mono(ethylacetoacetate)titanium,diethoxy•bis(ethylacetoacetate)titanium,di-n-propoxy•bis(ethylacetoacetate)titanium,di-i-propoxy•bis(ethylacetoacetate)titanium,di-n-butoxy•bis(ethylacetoacetate)titanium,di-sec-butoxy•bis(ethylacetoacetate)titanium,di-t-butoxy•bis(ethylacetoacetate)titanium,monoethoxy•tris(ethylacetoacetate)titanium,mono-n-propoxy•tris(ethylacetoacetate)titanium,mono-i-propoxy•tris(ethylacetoacetate)titanium,mono-n-butoxy•tris(ethylacetoacetate)titanium,mono-sec-butoxy•trig(ethylacetoacetate)titanium,mono-t-butoxy•tris(ethylacetoacetate)titanium,tetrakis(ethylacetoacetate)titanium,mono(acetylacetonato)tris(ethylacetoacetate)titanium,bi(acetylacetonato)bis(ethylacetoacetate)titanium andtris(acetylacetonato)mono(ethylacetoacetate)titanium; zirconium chelatecompounds such as

[0118] triethoxy•monox(acetylacetonato)azirconium,tri-n-propoxy•mono(acetylacetonato)azirconium,tri-i-propoxy•mono(acetylacetonato)zirconium,tri-n-butoxy•mono(acetylacetonato)zirconium,tri-sec-butoxy•mono(acetylacetonato)zirconium,tri-t-butoxy•mono(acetylacetonato)zirconium,diethoxy•bis(acetylacetonato)zirconium,di-n-propoxy•bis(acetylacetonato)zirconium,di-i-propoxy•bis(acetylacetonato)zirconium,di-n-butoxy•bis(acetylacetonato)zirconium,di-sec-butoxy•bis(acetylacetonato)zirconium,di-t-butoxy•bis(acetylacetonato)zirconium,monoethoxy•tris(acetylacetonato)zirconium,mono-n-propoxy•tris(acetylacetonato)zirconium,mono-i-propoxy•tris(acetylacetonato)zirconium,mono-n-butoxy•tris(acetylacetonato)zirconium,mono-sec-butoxy•tris(acetylacetonato)zirconium,mono-t-butoxy•tris(acetylacetonato)zirconium,tetrakis(acetylacetonato)zirconium,triethoxy•mono(ethylacetoacetate)zirconium,tri-n-propoxy•mono(ethylacetoacetate)zirconium,tri-i-propoxy•mono(ethylacetoacetate)zirconium,tri-n-butoxy•mono(ethylacetoacetate)zirconium,tri-sec-butoxy•mono(ethylacetoacetate)zirconium,tri-t-butoxy•mono(ethylacetoacetate)zirconium,diethoxy•bis(ethylacetoacetate)zirconium,di-n-propoxy•bis(ethylacetoacetate)zirconium,di-i-propoxy•bis(ethylacetoacetate)zirconium,di-n-butoxy•bis(ethylacetoacetate)zirconium,di-sec-butoxy•bis(ethylacetoacetate)zirconium,di-t-butoxy•bis(ethylacetoacetate)zirconium,monoethoxy•tris(ethylacetoacetate)zirconium,mono-n-propoxy•tris(ethylacetoacetate)zirconium,mono-i-propoxy•tris(ethylacetoacetate)zirconium,mono-n-butoxy•tris(ethylacetoacetate)zirconium,mono-sec-butoxy•tris(ethylacetoacetate)zirconium,mono-t-butoxy•tris(ethylacetoacetate)zirconium,tetrakis(ethylacetoacetate)zirconium,mono(acetylacetonato)tris(ethylacetoacetate)zirconium,bis(acetylacetonato)bis(ethylacetoacetate)zirconium andtris(acetylacetonato)mono(ethylacetoacetate)zirconium; and aluminumchelate compounds such as tris(acetylacetonato)aluminum andtris(ethylacetoacetate)aluminum.

[0119] Examples of the organic acid used as a catalyst include aceticacid, propionic acid, butanoic acid, pentanoic acid, hexoic acid,heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalicacid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallicacid, butyric acid, mellitic acid, arachidonic acid, mikimic acid,2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenicacid, salicylic acid, benzoic acid, p-aminobenzoic acid,p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid,dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formicacid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citricacid and tartaric acid.

[0120] Examples of the inorganic acid used as a catalyst includehydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid andphosphoric acid.

[0121] Examples of the organic base used as a catalyst include pyridine,pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine,triethylamine, monoethanolamine, diethanolamine,dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine,diazabicyclooctane, diazabicyclononane, diazabicycloundecene andtetramethylammonium hydroxide.

[0122] Examples of the inorganic base used as a catalyst includeammonia, sodium hydroxide, potassium hydroxide, barium hydroxide andcalcium hydroxide.

[0123] Out of these, a metal chelate compound, an organic acid or aninorganic acid is preferably used as a catalyst and a titanium chelatecompound or an organic acid is more preferably used.

[0124] These compounds may be used alone or in combination of two ormore as a catalyst.

[0125] The amount of the catalyst is generally 0.001 to 10 parts byweight, preferably 0.01 to 10 parts by weight based on 100 parts byweight of the compound represented by the above formula (18) in terms ofSiO₂.

[0126] Further, it is preferred to remove the residual water and analcohol formed as a reaction by-product after the hydrolysis and/orcondensation of the compound represented by the above formula (18).

[0127] The amount of the component (B) is preferably 10 to 95 parts byweight, more preferably 10 to 90 parts by weight, much more preferably20 to 90 parts by weight, particularly preferably 20 to 70 parts byweight based on 100 parts by weight of the total of the components (A)and (B). When the amount of the component (B) is smaller than 10 partsby weight, the obtained refractive index changing material is apt to bebrittle and when the amount is larger than 90 parts by weight, theobtained refractive index difference tends to be small.

[0128] (C) Radiation Sensitive Decomposer

[0129] The radiation sensitive decomposer (C) used in the presentinvention can be a radiation sensitive acid generator or a radiationsensitive base generator. In this case, it is preferred to use aradiation sensitive acid generating agent as the radiation sensitivedecomposer (C) when an acid decomposable polymer is used as thedecomposable polymer (A) and a radiation sensitive base generator as theradiation sensitive decomposer (C) when a base decomposable polymer isused as the decomposable polymer (A).

[0130] The above radiation sensitive acid generator may be atrichloromethyl-s-triazine, diaryl iodonium salt, triaryl sulfoniumsalt, quaternary ammonium salt or sulfonic acid ester.

[0131] Examples of the trichloromethyl-s-triazine include

[0132] 2,4,6-tris(trichloromethyl)-s-triazine,2-phenyl-4,6-bis(trichloromethyl)-s-triazine,2-(4-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(2-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(2-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methylthiophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methylthiophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(2-methylthiophenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine,2-(2-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxy-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methoxy-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(2-methoxy-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(3,4,5-trimethoxy-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methylthio-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methylthio-β-styryl)-4,6-bis(trichloromethyl)-s-triazine,2-(3-methylthio-β-styryl) -4,6-bis(trichloromethyl)-s-triazine,2-piperonyl-4,6-bis(trichloromethyl)-s-triazine,2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine,2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis (trichloromethyl)-s-triazineand2-[2-(4-diethylamino-2-methylphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine.

[0133] Examples of the above diaryl iodonium salt includediphenyliodonium tetrafluoroborate, diphenyliodoniumhexafluorophosphonate, diphenyliodoniumhexafluoroarsenate,diphenyliodonium trifluoromethane sulfonate, diphenyliodoniumtrifluoroacetate, diphenyliodonium-p-toluene sulfonate, diphenyliodoniumbutyltris(2,6-difluorophenyl)borate, diphenyliodoniumhexyltris(p-chlorophenyl)borate, diphenyliodoniumhexyltris(3-trifluoromethylphenyl)borate, 4-methoxyphenylphenyliodoniumtetrafluoroborate, 4-methoxyphenylphenyliodonium hexafluorophosphonate,4-methoxyphenylphenyliodonium hexafluoroarsenate,4-methoxyphenylphenyliodonium trifluoromethane sulfonate,4-methoxyphenylphenyliodonium trifluoroacetate,4-methoxyphenylphenyliodonium-p-toluene sulfonate,4-methoxyphenylphenyliodonium butyltris(2,6-difluorophenyl)borate,4-methoxyphenylphenyliodonium hexyltris(p-chlorophenyl)borate,4-methoxyphenylphenyliodonium hexyltris(3-trifluoromethylphenyl)borate,bis(4-tert-butylphenyl)iodonium tetrafluoroborate,bis(4-tert-butylphenyl)iodonium hexafluoroarsenate,bis(4-tert-butylphenyl)iodonium trifluoromethane sulfonate,bis(4-tert-butylphenyl)iodonium trifluoroacetate,bis(4-tert-butylphenyl)iodonium-p-toluene sulfonate,bis(4-tert-butylphenyl)iodonium butyltris(2,6-difluorophenyl)borate,bis(4-tert-butylphenyl)iodonium hexyltris(p-chlorophenyl)borate andbis(4-tert-butylphenyl)iodoniumhexyltris(3-trifluoromethylphenyl)borate.

[0134] Examples of the above triaryl sulfonium salt includetriphenylsulfonium tetrafluoroborate, triphenylsulfoniumhexafluorophosphonate, triphenylsulfonium hexafluoroarsenate,triphenylsulfonium trifluoromethane sulfonate, triphenylsulfoniumtrifluoroacetate, triphenylsulfonium-p-toluene sulfonate,triphenylsulfonium butyltris(2,6-difluorophenyl)borate,triphenylsulfonium hexyltris(p-chlorophenyl)borate, triphenylsulfoniumhexyltris(3-trifluoromethylphenyl)borate,4-methoxyphenyldiphenylsulfonium tetrafluoroborate,4-methoxyphenyldiphenylsulfonium hexafluorophosphonate,4-methoxyphenyldiphenylsulfonium hexafluoroarsenate,4-methoxyphenyldiphenylsulfonium trifluoromethane sulfonate,4-methoxyphenyldiphenylsulfonium trifluoroacetate,4-methoxyphenyldiphenylsulfonium-p-toluene sulfonate,4-methoxyphenyldiphenylsulfonium butyltris(2,6-difluorophenyl)borate,4-methoxyphenyldiphenylsulfonium hexyltris(p-chlorophenyl)borate,4-methoxyphenyldiphenylsulfoniumhexyltris(3-trifluoromethylphenyl)borate,4-phenylthiophenyldiphenylsulfonium tetrafluoroborate,4-phenylthiophenyldiphenylsulfonium hexafluorophosphonate,4-phenylthiophenyldiphenylsulfonium hexafluoroarsenate,4-phenylthiophenyldiphenylsulfonium trifluoromethane sulfonate,4-phenylthiophenyldiphenylsulfonium trifluoroacetate,4-phenylthiophenyldiphenylsulfonium-p-toluene sulfonate,4-phenylthiophenyldiphenylsulfonium butyltris(2,6-difluorophenyl)borate,4-phenylthiophenyldiphenylsulfonium hexyltris(p-chlorophenyl)borate,4-phenylthiophenyldiphenylsulfoniumhexyltris(3-trifluoromethylphenyl)borate,4-hydroxy-1-naphthalenyl)dimethylsulfonium tetrafluoroborate,4-hydroxy-1-naphthalenyl)dimethylsulfonium hexafluorophosphonate,4-hydroxy-1-naphthalenyl)dimethylsulfonium hexafluoroarsenate,4-hydroxy-1-naphthalenyl)dimethylsulfonium trifluoromethane sulfonate,4-hydroxy-1-naphthalenyl)dimethylsulfonium trifluoroacetate,4-hydroxy-1-naphthalenyl)dimethylsulfonium-p-toluene sulfonate,4-hydroxy-1-naphthalenyl)dimethylsulfoniumbutyltris(2,6-difluorophenyl)borate, 4-hydroxy1-naphthalenyl)dimethylsulfonium hexyltris(p-chlorophenyl)borate and4-hydroxy-1-naphthalenyl)dimethylsulfoniumhexyltris(3-trifluoromethylphenyl)borate.

[0135] Examples of the above quaternary ammonium salt includetetramethylammonium tetrafluoroborate, tetramethylammoniumhexafluorophosphonate, tetramethylammonium hexafluoroarsenate,tetramethylammonium trifluoromethane sulfonate, tetramethylammoniumtrifluoroacetate, tetramethylammonium-p-toluene sulfonate,tetramethylammonium butyltris(2,6-difluorophenyl)borate,tetramethylammonium hexyltris(p-chlorophenyl)borate, tetramethylammoniumhexyltris(3-trifluoromethylphenyl)borate, tetrabutylammoniumtetrafluoroborate, tetrabutylammonium hexafluorophosphonate,tetrabutylammonium hexafluoroarsenate, tetrabutylammoniumtrifluoromethane sulfonate, tetrabutylammonium trifluoroacetate,tetrabutylammonium-p-toluene sulfonate, tetrabutylammoniumbutyltris(2,6-difluorophenyl)borate, tetrabutylammoniumhexyltris(p-chlorophenyl)borate, tetrabutylammoniumhexyltris(3-trifluoromethylphenyl)borate, benzyltrimethylammoniumtetrafluoroborate, benzyltrimethylammonium hexafluorophosphonate,benzyltrimethylammonium hexafluoroarsenate, benzyltrimethylammoniumtrifluoromethane sulfonate, benzyltrimethylammonium trifluoroacetate,benzyltrimethylammonium-p-toluene sulfonate, benzyltrimethylammoniumbutyltris(2,6-difluorophenyl)borate, benzyltrimethylammoniumhexyltris(p-chlorophenyl)borate, benzyltrimethylammoniumhexyltris(3-trifluoromethylphenyl)borate, benzyldimethylphenylammoniumtetrafluoroborate, benzyldimethylphenylammonium hexafluorophosphonate,benzyldimethylphenylammonium hexafluoroarsenate,benzyldimethylphenyiammonium trifluoromethane sulfonate,benzyldimethylphenylammonium trifluoroacetate,benzyldimethylphenylammonium-p-toluene sulfonate,benzyldimethylphenylammonium butyltris(2,6-difluorophenyla)borate,benzyldimethylphenylammonium hexyltris(p-chlorophenyl)borate,benzyldimethylphenylammonium hexyltris(3-trifluoromethylphenyl)borate,N-cinnamylideneethylphenylammonium tetrafluoroborate,N-cinnamylideneethylphenylammonium hexafluorophosphonate,N-cinnamylideneethylphenylammonium hexafluoroarsenate,N-cinnamylideneethylphenylammonium trifluoromethane sulfonate,N-cinnamylideneethylphenylammonium trifluoroacetate,N-cinnamylideneethylphenylammonium-p-toluene sulfonate,N-cinnamylideneethylphenylammonium butyltris(2,6-difluorophenyl)borate,N-cinnamylideneethylphenylammonium hexyltris(p-chlorophenyl)borate andN-cinnamylideneethylphenylammoniumhexyltris(3-trifluoromethylphenyl)borate.

[0136] Examples of the above sulfonic acid ester includeα-hydroxymethylbenzoin-p-toluenesulfonic acid ester,α-hydroxymethylbenzoin-trifluoromethanesulfonic acid ester,α-hydroxymethylbenzoin-methanesulfonic acid ester,pyrogallol-tri(p-toluenesulfonic acid)ester,pyrogallol-tri(trifluoromethanesulfonic acid) ester,2,4-pyrogallol-trimethanesulfonic acid ester,2,4-dinitrobenzyl-p-toluenesulfonic acid ester,2,4-dinitrobenzyl-trifluoromethanesulfonic acid ester,2,4-dinitrobenzyl-methanesulfonic acid ester,2,4-dinitrobenzyl-1,2-naphthoquinonediazido-5-sulfonic acid ester,2,6-dinitrobenzyl-p-toluenesulfonic acid ester,2,6-dinitrobenzyl-trifluoromethanesulfonic acid ester,2,6-dinitrobenzyl-methanesulfonic acid ester,2,6-dinitrobenzyl-1,2-naphthoquinonediazido-5-sulfonic acid ester,2-nitrobenzyl-p-toluenesulfonic acid ester,2-nitrobenzyl-trifluoromethanesulfonic acid ester,2-nitrobenzyl-methanesulfonic acid ester,2-nitrobenzyl-1,2-naphthoquinonediazido-5-sulfonic acid ester,4-nitrobenzyl-p-toluenesulfonic acid ester,4-nitrobenzyl-trifluoromethanesulfonic acid ester,4-nitrobenzyl-methanesulfonic acid ester,4-nitrobenzyl-1,2-naphthoquinonediazido-5-sulfonic acidester,N-hydroxynaphthalimide-p-toluenesulfonic acid ester,N-hydroxynaphthalimide-trifluoromethanesulfonic acid ester,N-hydroxynaphthalimide-methanesulfonic acid ester,N-hydroxy-5-norbornene-2,3-dicarboxyimide-p-toluensulfonic acid ester,N-hydroxy-5-norbornene-2,3-dicarboxyimidetrifluoromethanesulfonic acidester, N-hydroxy-5-norbornene-2,3-dicarboxyimidemethanesulfonic acidester,2,4,6,3′,4′,5′-hexahydroxybenzophenone-1,2-naphthoquinonediazido-4-sulfonicacid ester and1,1,1-tri(p-hydroxyphenyl)ethane-1,2-naphthoquinonediazido-4-sulfonicacid ester.

[0137] Out of these compounds,2-(3-chlorophenyl)-bis(4,6-trichloromethyl)-s-triazine,2-(4-methoxyphenyl)-bis(4,6-trichloromethyl)-s-triazine,2-(4-methylthiophenyl)-bis(4,6-trichloromethyl)-s-triazine,2-(4-methoxy-β-styryl)-bis(4,6-trichloromethyl)-s-triazine,2-piperonyl-bis(4,6-trichloromethyl)-s-triazine,2-[2-(furan-2-yl)ethenyl]-bis(4,6-trichloromethyl)-s-triazine,2-[2-(5-methylfuran-2-yl)ethenyl]-bis(4,6-trichloromethyl)-s-triazine,2-[2-(4-diethylamino-2-methylphenyl)ethenyl]-bis(4,6-trichloromethyl)-s-triazineand 2-(4-methoxynaphthyl)-bis(4,6-trichloromethyl)-s-triazine arepreferred as trichloromethyl-s-triazines; diphenyliodoniumtrifluoroacetate, diphenyliodonium trifluoromethane sulfonate,4-methoxyphenylphenyliodonium trifluoromethane sulfonate and4-methoxyphenylphenyliodonium trifluoroacetate are preferred asdiaryliodonium salts; triphenylsulfonium trifluoromethane sulfonate,triphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfoniumtrifluoromethane sulfonate, 4-methoxyphenyldiphenylsulfoniumtrifluoroacetate, 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonate and 4-phenylthiophenyldiphenylsulfonium trifluoroacetate arepreferred as triarylsulfonium salts; tetramethylammoniumbutyltris(2,6-difluorophenyl)borate, tetramethylammoniumhexyltris(p-chlorophenyl)borate, tetramethylammoniumhexyltris(3-trifluoromethylphenyl)borate, benzyldimethylphenylammoniumbutyltris(2,6-difluorophenyl)borate, benzyldimethylphenylammoniumhexyltris(p-chlorophenyl)borate and benzyldimethylphenylammoniumhexyltris(3-trifluoromethylphenyl)borate are preferred as quaternaryammonium salts; and 2,6-dinitrobenzyl-p-toluenesulfonic acid ester,2,6-dinitrobenzyl-trifluoromethanesulfonic acid ester,N-hydroxynaphthalimide-p-toluenesulfonic acid ester andN-hydroxynaphthalimide-trifluoromethanesulfonic acid ester are preferredas sulfonic acid esters.

[0138] What are disclosed by JP-A 4-330444, “Polymer”, pp. 242-248, vol.46, No. 6 (1997) and U.S. Pat. No. 5,627,010 are advantageously used asthe above radiation sensitive base generator. However, the radiationsensitive base generator is not limited to these if it generates a baseupon exposure to radiation.

[0139] The radiation sensitive base generator in the present inventionis preferably an optically active carbamate such as triphenyl methanol,benzyl carbamate or benzoin carbamate; amide such as O-carbamoylhydroxylamide, O-carbamoyloxime, aromatic sulfonamide, alpha-lactam orN-(2-allylethynyl)amide, or other amide; oxime ester,α-aminoacetophenone or cobalt complex.

[0140] Examples of the radiation sensitive base generator includecompounds represented by the following formulas (19) to (29):

[0141] wherein R⁷⁶ is an alkyl group having 1 to 6 carbon atoms, alkoxygroup having 1 to 6 carbon atoms, thioalkyl group having 1 to 6 carbonatoms, dialkylamino group having 1 to 6 carbon atoms, piperidyl group,nitro group, hydroxy group, mercapto group, aryl group, fluorine atom,chlorine atom or bromine atom, k is an integer of 0 to 3, R⁷⁷ is ahydrogen atom, alkyl group having 1 to 6 carbon atoms or aryl group, andR⁷⁸ and R⁷⁹ are each independently a hydrogen atom, alkyl group having 1to 6 carbon atoms, aryl group or benzyl group, or R⁷⁸ and R⁷⁹ may bebonded together to form a cyclic structure having 5 to 6 carbon atomstogether with a nitrogen atom bonded thereto,

[0142] wherein R⁸⁰ is an alkyl group having 1 to 6 carbon atoms, alkoxygroup having 1 to 6 carbon atoms, thioalkyl group having 1 to 6 carbonatoms, dialkylamino group having 1 to 6 carbon atoms, piperidyl group,nitro group, hydroxy group, mercapto group or aryl group, R⁸¹ is ahydrogen atom, alkyl group having 1 to 6 carbon atoms or aryl group, andR⁸² and R⁸³ are each independently a hydrogen atom, alkyl group having 1to 6 carbon atoms, aryl group or benzyl group, or R⁸² and R⁸³ may bebonded together to form a cyclic structure having 5 to 6 carbon atomstogether with a nitrogen atom bonded thereto,

[0143] wherein R⁸⁴ is an alkyl group having 1 to 6 carbon atoms or arylgroup, and R⁸⁵ and R⁸⁶ are each independently a hydrogen atom, alkylgroup having 1 to 6 carbon atoms, aryl group or benzyl group, or R⁸⁵ andR⁸⁶ may be bonded together to form a cyclic structure having 5 to 6carbon atoms together with a nitrogen atom bonded thereto,

[0144] wherein R⁸⁷ and R⁸⁸ are each independently an alkyl group having1 to 6 carbon atoms or aryl group,

[0145] wherein R⁸⁹, R⁹⁰ and R⁹¹ are each independently an alkyl grouphaving 1 to 6 carbon atoms or aryl group,

[0146] wherein R⁹² is an alkyl group having 1 to 6 carbon atoms, alkoxygroup having 1 to 6 carbon atoms, thioalkyl group having 1 to 6 carbonatoms, dialkylamino group having 1 to 6 carbon atoms, piperidyl group,nitro group, hydroxy group, mercapto group or aryl group, R⁹³ is ahydrogen atom, alkyl group having 1 to 6 carbon atoms or aryl group, andR⁹⁴, R⁹⁵ and R⁹⁶ are each independently a hydrogen atom, alkyl grouphaving 1 to 6 carbon atoms, aryl group or benzyl group,

[0147] wherein R⁹⁷ is an alkyl group having 1 to 6 carbon atoms, alkoxygroup having 1 to 6 carbon atoms, thioalkyl group having 1 to 6 carbonatoms, dialkylamino group having 1 to 6 carbon atoms, piperidyl group,nitro group, hydroxy group, mercapto group or aryl group, R⁹⁸ and R⁹⁹are each independently a hydrogen atom, hydroxyl group, mercapto group,cyano group, phenoxy group, alkyl group having 1 to 6 carbon atoms,fluorine atom, chlorine atom, bromine atom or aryl group, and R¹⁰⁰ andR¹⁰¹ are each independently a hydrogen atom, alkyl group having 1 to 6carbon atoms, aryl group or benzyl group, or R¹⁰⁰ and R¹⁰¹ may be bondedtogether to form a cyclic structure having 5 to 6 carbon atoms togetherwith a nitrogen atom bonded thereto,

[0148] wherein R¹⁰² and R¹⁰³ are each independently an alkyl grouphaving 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms,thioalkyl group having 1 to 6 carbon atoms, dialkylamino group having 1to 6 carbon atoms, piperidyl group, nitro group, hydroxy group, mercaptogroup or aryl group, R¹⁰⁴ to R¹⁰⁷ are each independently a hydrogenatom, hydroxyl group, mercapto group, cyano group, phenoxy group, alkylgroup having 1 to 6 carbon atoms, fluorine atom, chlorine atom, bromineatom or aryl group, and A⁵ is a divalent atomic group formed byexcluding two hydrogen atoms bonded to one or two nitrogen atoms of amonoalkylamine, piperazine, aromatic diamine or aliphatic diamine,

[0149] wherein R¹⁰⁸ and R¹⁰⁹ are each independently an alkyl grouphaving 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms,thioalkyl group having 1 to 6 carbon atoms, dialkylamino group having 1to 6 carbon atoms, piperidyl group, nitro group, hydroxy group, mercaptogroup or aryl group, R¹¹⁰ and R¹¹¹ are each independently a hydrogenatom, hydroxyl group, mercapto group, cyano group, phenoxy group, alkylgroup having 1 to 6 carbon atoms, fluorine atom, chlorine atom, bromineatom or aryl group, R¹¹² to R¹¹⁵ are each independently a hydrogen atom,alkyl group having 1 to 6 carbon atoms, aryl group or benzyl group, orR¹¹² and R¹¹³ and R¹¹⁴ and R¹¹⁵ may be bonded together to form a cyclicstructure having 5 to 6 carbon atoms together with nitrogen atoms bondedthereto, and A⁶ is an alkylene group having 1 to 6 carbon atoms,cyclohexylene group, phenylene group or single bond,

[0150] wherein R¹¹⁶ to R¹¹⁸ are each independently a hydrogen atom,fluorine atom, chlorine atom, bromine atom, alkyl group having 1 to 6carbon atoms, alkenyl group having 1 to 6 carbon atoms, alkynyl grouphaving 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms oraryl group,

L_(m)CO³⁺·3[(R¹¹⁹)₃R¹²⁰]⁻  (29)

[0151] wherein L is at least one ligand selected from the groupconsisting of ammonia, pyridine, imidazole, ethylene diamine,trimethylene diamine, tetramethylene diamine, hexamethylene diamine,propylene diamine, 1,2-cyclohexane diamine, N,N-diethylethylene diamineand diethylene triamine, m is an integer of 2 to 6, R¹¹⁹ is an arylgroup, and R¹²⁰ is an alkyl group having 1 to 18 carbon atoms.

[0152] In all the above formulas (19) to (29), the alkyl group may belinear, branched or cyclic. The aryl group includes an alkenyl groupsuch as vinyl or propylenyl; alkynyl group such as acetylenyl; phenylgroup, naphthyl group and anthracenyl group, and also what contain afluorine atom, chlorine atom, bromine atom, haloalkyl group, hydroxylgroup, carboxyl group, mercapto group, cyano group, nitro group, azidogroup, dialkylamino group, alkoxy group or thioalkyl group substitutedfor the hydrogen atoms of the above groups.

[0153] Out of these radiation sensitive base generators, preferred are2-nitrobenzylcyclohexyl carbamate, triphenyl methanol,o-carbamoylhydroxylamide, o-carbamoyloxime,[[(2,6-dinitrobenzyl)oxy]carbonyl]cyclohexylamine,bis[[(2-nitrobenzyl)oxy]carbonyl]hexane 1,6-diamine,4-(methylthiobenzoyl)-1-methyl-1-morpholinoethane,(4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane,N-(2-nitrobenzyloxycarbonyl)pyrrolidine, hexamminecobalt(III)tris(triphenylmethylborate) and2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone.

[0154] The above radiation sensitive decomposer (C) is preferably usedin an amount of 0.01 part or more by weight, more preferably 0.05 partor more by weight based on 100 parts by weight of the total of thedecomposable polymer (A) and the non-decomposable compound (B). When theamount of the component (C) is smaller than 0.01 part by weight,sensitivity to radiation tends to be lower. The upper limit value ispreferably 30 parts by weight, more preferably 20 parts by weight.

[0155] (D) stabilizer

[0156] The stabilizer (D) used in the present invention has the functionof stabilizing the residual decomposable polymer (A) existent in therefractive index changing material after exposure to radiation toprovide stability to an acid or base. This stabilization prevents achange in refractive index and hence the deterioration of a refractiveindex pattern formed by the method of the present invention even when itis used under the condition that light having a wavelength close to thewavelength used to change the refractive index passes therethrough.

[0157] Examples of the above stabilizer (D) include amino compound,epoxy compound, thuirane compound, oxetane compound, alkoxymethylmelamine compound, alkoxymethyl glycoluril compound, alkoxymethylbenzoguanamine compound, alkoxymethyl urea compound, isocyanatecompound, cyanate compound, oxazoline compound, oxazine compound andsilyl compound (silyl halide compound and other silyl compound).

[0158] Examples of the above amino compound include ammonia,trimethylamine, triethylamine, tripropylamine, tributylamine,tripentylamine, trihexylamine, tricyclohexylamine, triphenylamine,tribenzylamine, aniline, ethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, 1,3-diaminopropane,1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane,1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane,1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane,1,4-diaminocyclohexane, 1,3-cyclohexanebis(methylamine),1,3-propan-2-ol, 2,2′,2″-triaminotriethylamine,1,4-diamino-2,2,3,3-tetrafluoropentane,1,5-diamino-2,2,3,3,4,4-hexafluoropentane, melamine, benzoguanamine,acetoguanamine, acryloguanamine, paramine, amidol, m-phenylenediamine,p-phenylenediamine, p,p′-diaminodiphenylmethane, diaminodiphenylsulfone,1,8-diaminonaphthalene, 3,5-diamino-1,2,4-triazole,2-chloro-4,6-diamino-S-triazine, 2,6-diaminopyridine,3,3′-diaminobenzidine, bis(4-aminophenyl)ether, m-xylylenediamine,p-xylylenediamine, 1,2,4,5-benzenetetramine, 2,4-diamino-1,3,5-triazine,4,4′-diaminobenzophenone, 3,3′,4,4′-tetraaminobenzophenone,triaminobenzene, 4,4′-thiodianiline,2,3,5,6-tetrabromo-p-xylylenediamine,2,3,5,6-tetrachloro-p-xylylenediamine,4,5-methylenedioxy-1,2-phenylenediamine and2,2′-bis(5-aminopyridyl)sulfide.

[0159] The above epoxy compound is a bisphenol A epoxy resin, bisphenolF epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin,cyclic aliphatic epoxy resin or aliphatic polyglycidyl ether.,

[0160] Examples of commercially available products of the abovecompounds are given below. Commercially available products of thebisphenol A epoxy resin include Epicoat 1001, 1002, 1003, 1004, 1007,1009, 1010 and 828 (of Yuka Shell Epoxy Co., Ltd.), those of thebisphenolF epoxy resin include Epicoat 807 (of Yuka Shell Co., Ltd.),those of the phenol novolak epoxy resin include Epicoat 152 and 154 (ofYuka Shell Epoxy Co., Ltd.) and EPPN201 and 202 (of Nippon Kayaku Co.,Ltd.), those of the cresol novolak epoxy resin include EOCN-102,EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025 and EOCN-1027 (of NipponKayaku Co., Ltd.) and Epicoat 180S75 (of Yuka Shell Epoxy Co., Ltd.),those of the cyclic aliphatic epoxy resin include CY175, CY177and CY179(of CIBA-GEIGYA.G.), ERL-4234, ERL-4299, ERL-4221 and ERL-4206 (ofU.C.C. Co., Ltd.), Showdyne 509 (of Showa Denko K. K.), Araldyte CY-182,CY-192 and CY-184 (of CIBA-GEIGY A.G.), Epichlon 200 and 400 (ofDainippon Ink and Chemicals, Inc.), Epicoat 871 and 872 (of Yuka ShellEpoxyCo.,Ltd.) and ED-5661and ED-5662 (of Ceranies Coating Co., Ltd.),and those of the aliphatic polyglycidyl ether include Epolite 100MF (ofKyoeisha Kagaku Co., Ltd.) and Epiol TMP (of NOF Corporation).

[0161] Besides the above compounds, phenylglycidyl ether, butylglycidylether, 3,3,3-trifluoromethylpropylene oxide, styrene oxide,hexafluoropropylene oxide, cyclohexene oxide, N-glycidylphthalimide,(nonafluoro-N-butyl)epoxide, perfluoroethylglycidyl ether,epichlorohydrin, epibromohydrin, N,N-diglycidylaniline and3-[2-(perfluorohexyl)ethoxy]-1,2-epoxypropane may be advantageously usedas an epoxy compound.

[0162] Examples of the above thiirane compound include those obtained bysubstituting the epoxy groups of the above epoxy compounds with anethylene sulfide group as shown in J. Org. Chem., 28, 229 (1963), forexample.

[0163] Examples of the above oxetane compound includebis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene (trade name of XDO, ofToagosei Chemical Industry Co., Ltd.),.bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]methane,bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]ether,bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]propane,bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]sulfone,bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]ketone,bis[(3-ethyl-3-oxetanylmethoxy)methyl-phenyl]hexafluoropropane,tri[(3-ethyl -3-oxetanylmethoxy)methyl]benzene andtetra[(3-ethyl-3-oxetanylmethoxy)methyl]benzene.

[0164] The above alkoxymethyl melamine compound, alkoxymethylbenzoguanamine compound, alkoxymethyl glycoluril compound andalkoxymethyl urea compound are obtained by substituting the methylolgroups of a methylol melamine compound, methylol benzoguanaminecompound, methylol glycoluril compound and methylol urea compound withan alkoxymethyl group, respectively. The type of the alkoxymethyl groupis not particularly limited, as exemplified by methoxymethyl group,ethoxymethyl group, propoxymethyl group and butoxymethyl group.

[0165] Commercially available products of the above compounds includeSimel 300, 301, 303, 370, 325, 327, 701, 266, 267, 238, 1141, 272, 202,1156, 1158, 1123, 1170 and 1174, and UFR65 and 300 (of Mitsui SianamidCo., Ltd.), and Nicalack Mx-750, Mx-032, Mx-706, Mx-708, Mx-40, Mx-31,Ms-11 and Mw-30 (of Sanwa Chemical Co., Ltd.).

[0166] Examples of the above isocyanate compound includephenylene-1,3-diisocyanate, phenylene-1,4-diisocyanate,1-methoxyphenylene-2,4-diisocyanate, 1-methylphenylene-2,4-diisocyanate,2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylenediisocyanate, 1,4-xylylene diusocyanate, biphenylene-4,4′-diisocyanate,3,3′-dimethoxybiphenylene-4,4′-diisocyanate,3,3′-dimethylbiphenylene-4,4′-diisocyanate,diphenylmethane-2,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate,3,3′-dimethoxydiphenylmethane-4,4′-diisocyanate,3,3′-dimethyldiphenylmethane-4,4′-diisocyanate,naphthylene-1,5-diisocyanate, cyclobutylene-1,3-diisocyanate,cyclopentylene-1,3-diisocyanate, cyclohexylene-1,3-diisocyanate,cyclohexylene-1,4-diisocyanate, 1-methylcyclohexylene-2,4-diisocyanate,1-methylcyclohexylene-2,6-diisocyanate,1-isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane,cyclohexane-1,3-bis(methylisocyanate),cyclohexane-1,4-bis(methylisocyanate), isophorone diisocyanate,dicyclohexylmethane-2,4′-diisocyanate,dicyclohexylmethane-4,4′-diisocyanate, ethylene diisocyanate,tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate,dodecamethylene-1,12-diisocyanate, lysine diisocyanate methyl ester andprepolymers having an isocyanate at both terminals obtained from areaction between a stoichiometrically excessive amount of an organicdiisocyanate thereof and a bifunctional active hydrogen-containingcompound.

[0167] The above diisocyanate may be used in combination with an organipolyisocyanate having a functionality of 3 or more, such asphenyl-1,3,5-triisocyanate, diphenylmethane-2,4,4′-truisocyanate,diphenylmethane-2,5,4′-triisocyanate,triphenylmethane-2,4′,4″-triusocyanate,triphenylmethane-4,4′,4″-truisocyanate,diphenylmethane-2,4,2′,4′-tetraisocyanate,diphenylmethane-2,5,2′,5′-tetraisocyanate,cyclohexane-1,3,5-triisocyanate,cyclohexane-1,3,5-tris(methylisocyanate),3,5-dimethylcyclohexane-1,3,5-tris(methylisocyanate),1,3,5-trimethylcyclohexane-1,3,5-tris(methylisocyanate),dicyclohexylmethane-2,4,2′-triisocyanate,dicyclohexylmethane-2,4,4′-triisocyanate or a prepolymer having anisocyanate at a terminal obtained from a reaction between astoichiometrically excessive amount of an organic polyisocyanate havinga functionality of 3 or more and a polyfunctional activehydrogen-containing compound having a functionality of 2 or more.

[0168] Examples of the above cyanate compound include 1,3-dicyanatebenzene, 1,4-dicyanate benzene, 1,3,5-tricyanate benzene, 1,3-, 1,4-,1,6-, 1,8-, 2,6- or 2,7-dicyanate naphthalene, 1,3,6-tricyanatenaphthalene, 2,2′- or 4,4′-dicyanate biphenyl,bis(4-cyanatephenyl)methane, 2,2-bis(4-cyanatephenyl)propane,2,2′-bis(3,5-dichloro-4-cyanatephenyl)propane,2,2-bis(4-cyanatephenyl)ethane, bis(4-cyanatephenyl)ether,bis(4-cyanatephenyl)thioether, bis(4-cyanatephenyl)sulfone,1,1,1,3,3,3-hexafluoro-2,2-bis(4-cyanatephenyl)propane,tris(4-cyanatephenyl)phosphite, tris(4-cyanatephenyl)phosphate andbenzene polynuclear polyisocyanate compounds obtained from a reactionbetween a phenol resin and a cyan halide (for example, JP-B 45-11712 andJP-B 55-9433) (the term “JP-B” as used herein means an “examinedJapanese patent publication”). A divalent cyanate compound derived froma bisphenol such as 2,2-bis(4-cyanatephenyl)propane is particularlypreferred because it is easily acquired, has excellent moldability andprovides favorable properties to the final cured product. A polycyanateobtained by reacting an initial condensate of a phenol and formaldehydewith a cyan halide is also useful.

[0169] Examples of the above oxazoline compound include2,2′-bis(2-oxazoline), 4-furan-2-ylmethylene-2-phenyl-4H-oxazol-5-one,1,4-bis(4,5-dihydro-2-oxazolyl)benzene,1,3-bis(4,5-dihydro-2-oxazolyl)benzene,2,3-bis(4-isopropenyl-2-oxazolin-2-yl)butane,2,2′-bis-4-benzyl-2-oxazoline,2,6-bis(isopropyl-2-oxazolin-2-yl)pyridine,2,2′-isopropylidenebis(4-tert-butyl-2-oxazoline),2,2′-isopropylidenebis(4-phenyl-2-oxazoline),2,2′-methylenebis(4-tert-butyl-2-oxazoline) and2,2′-methylenebis(4-phenyl-2-oxazoline).

[0170] Examples of the above oxazine compound include2,2′-bis(2-oxazine), 4-furan-2-ylmethylene-2-phenyl-4H-oxazyl-5-one,1,4-bis(4,5-dihydro-2-oxazyl)benzene,1,3-bis(4,5-dihydro-2-oxazyl)benzene,2,3-bis(4-isopropenyl-2-oxazin-2-yl)butane, 2,2′-bis-4-benzyl-2-oxazine,2,6-bis(isopropyl-2-oxazin-2-yl)pyridine,2,2′-isopropylidenebis(4-tert-butyl-2-oxazine),2,2′-isopropylidenebis(4-phenyl-2-oxazine),2,2′-methylenebis(4-tert-butyl-2-oxazine) and2,2′-methylenebis(4-phenyl-2-oxazine).

[0171] Examples of the above silyl halide compound includetetrahalogenosilanes such as tetrachlorosilane, tetrabromosilane,tetraiodosilane, trichlorobromosilane and dichlorodibromosilane;monoalkyltrihalogenosilanes such as methyltrichlorosilane,methyldichlorobromosilane and cyclohexyltrichlorosilane;monoaryltrihalogenosilanes such as phenyltrichlorosilane,naphthyltrichlorosilane, 4-chlorophenyltrichlorosilane andphenyldichlorobromosilane; monoaryloxytrihalogenosilanes such asphenoxytrichlorosilane and phenoxydichlorobromosilane;monoalkoxytrihalogenosilanes such as methoxytrichlorosilane andethoxytrichlorosilane; dialkyldihalogenosilanes such asdimethyldichlorosilane, methyl(ethyl)dichlorosilane andmethyl(cyclohexyl)dichlorosilane; monoalkylmonoaryldihalogenosilanessuch as methyl(phenyl)dichlorosilane; diaryldihalogenosilanes such asdiphenyldichlorosilane; diaryloxydihalogenosilanes such asdiphenoxydichlorosilane; monoalkylmonoaryloxydihalogenosilanes such asmethyl(phenoxy)dichlorosilane; monoarylmonoaryloxydihalogenosilanes suchas phenyl(phenoxy)dichlorosilane, dialkoxydihalogenosilanes such asdiethoxydichlorosilane; monoalkylmonoalkoxydichlorosilanes such asmethyl(ethoxy)dichlorosilane; monoarylmonoethoxydichlorosilanes such asphenyl(ethoxy)dichlorosilane; trialkylmonohalogenosilanes such astrimethylchlorosilane, dimethyl(ethyl)chlorosilane anddimethyl(cyclohexyl)chlorosilane; dialkylmonoarylmonohalogenosilanessuch as dimethyl(phenyl)chlorosilane; monoalkyldiarylmonohalogenosilanessuch as methyl(diphenyl)chlorosilane; triaryloxymonohalogenosilanes suchas triphenoxychlorosilane; monoalkyldiaryloxymonohalogenosilanes such asmethyl(diphenoxy)chlorosilane; monoaryldiaryloxymonohalogenosilanes suchas phenyl(diphenoxy)chlorosilane; dialkylmonoaryloxymonohalogenosilanessuch as dimethyl(phenoxy)chlorosilane;diarylmonoaryloxymonohalogenosilanes such asdiphenyl(phenoxy)chlorosilane;monoalkylmonoarylmonoaryloxymonohalgenosilanes such asmethyl(phenyl)(phenoxy)chlorosilane; triethoxymonohalogenosilanes suchas triethoxychlorosilane; and oligomers thereof such as dimer, trimer,tetramer and pentamer of tetrachlorosilane.

[0172] Examples of the above other silyl compound includehexamethyldisilazane, t-butyldimethylchlorosilane,bis(trimethylsilyl)trifluoroacetamide, diethylaminotrimethylsilane,trimethylsilanol, hexamethyldisiloxane,chloromethyldimethylethoxysilane, acetyltriphenylsilane,ethoxytriphenylsilane, triphenylsilanol, triethylsilanol,tripropylsilanol, tributylsilanol, hexaethyldisiloxane,trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane,triethylethoxysilane, acetoxyethyldimethylchlorosilane,1,3-bis(hydroxybutyl)tetramethyldisiloxane,1,3-bis(hydroxypropyl)tetramethyldisiloxane, γ-aminopropylmethoxysilane,γ-aminopropylethoxysilane,N-β(aminoethyl)-γ-aminopropyltrimethoxysilane,N-β(aminoethyl)-γ-aminopropylmethyldimethoxysilane,N-phenyl-γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane,γ-dibutylaminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane,N-β(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane•hydrochlorate,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane, vinyltrimethoxysilane,vinyltriethoxysilane, vinyltrichlorosilane,vinyltris(β-methoxyethoxy)silane, γ-glycidoxypropylmethyldiethoxysilane,γ-glycidoxypropyltriethoxysilane,γ-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-chloropropyltrimethoxysilane, trimethylchlorosilane,hexamethyldisilazane, N-trimethylsilylimidazole,bis(trimethylsilyl)urea, trimethylsilylacetamide,bistrimethylsilylacetamide, trimethylsilylisocyanate,trimethylmethoxysilane, trimethylethoxysilane, methyltrimethoxysilane,methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane,t-butyldimethylchlorosilane, t-butyldiphenylchlorosilane,triisopropylchlorosilane, n-propyltrimethoxysilane,isobutyltrimethoxysilane, n-hexyltrimethoxysilane,n-decyltrimethoxysilane, n-hexadecyltrimethoxysilane,1,6-bis(trimethoxysilyl)hexane, dimethylsilyldiisocyanate,methylsilyltriisocyanate, phenyltrimethoxysilane,diphenyldimethoxysilane and phenylsilyltriisocyanate.

[0173] Out of these, the stabilizer (D) used in the present invention ispreferably an amino compound, epoxy compound, thiirane compound, oxetanecompound, oxazoline compound, oxazine compound, silyl compound,isocyanate compound or cyanate compound, more preferably an aminocompound, epoxy compound, thiirane compound, oxetane compound, oxazolinecompound or oxazine compound. It is particularly preferablyethylenediamine, phenylglycidyl ether, 3-phenoxypropylene sulfide,3,3,3-trifluoropropylene oxide, hexamethyldisilazane,γ-aminopropylmethoxysilane, γ-glycidoxypropyltrimethoxysilane ormethylsilyltriisocyanate.

[0174] These stabilizers (D) maybe used alone or in combination of twoor more. The amount of the component (D) may be excessive so that theresidual decomposable polymer (A) can react to the full but it isgenerally 10 parts or more by weight, preferably 30 parts or more byweight based on 100 parts by weight of the component (A). When theamount of the component (D) is smaller than 10 parts by weight, thestability of the refractive index changing material may becomeunsatisfactory due to an imcomplete reaction.

[0175] A catalyst may be used in combination with the stabilizer (D).Use of the catalyst promotes a reaction between the components (D) andthe residual decomposable polymer (A).

[0176] The catalyst is an acidic catalyst, basic catalyst or quaternaryonium.

[0177] Example of the acidic catalyst include organic acids such asacetic acid, methanesulfonic acid, p-toluenesulfonic acid; and inorganicacids and trifluoromethasulfonic acid, sulfonic acid and nitric acid.Example of the catalyst include alkaly metal carbonates such as sodiumcarbonate, potassium carbonate and lithium carbonate; alkali metalbicarbonates such as sodium bicarbonate, potassium bicarbonate andlithium bicarbonate; alkali metal acetates such as sodium acetate;alkali metal hydrides such as lithium hydride, sodium hydride andpotasium hydride; alkali metal hydroxyde such as sodium hydroxide,potasium hydroxyde and lithium hydroxide; alkali metal alkoxides such assodium methoxide, sodium athoxide, potasium t-butoxide and lithiummothoxide; mercaptan alkali metals such as methyl mercaptan sodium andethyl mercaptan sodium; organic amides such as triethylamine,tributylamine, diisopropylethylamine, N-methylmorpholine, pyridine,4-(N,N-dimethylamino)pyridine, N,N-dimethylamine, N,N-diethylamiline,1,5-diazabicyclo[4.3.0]non-5ene, 1,4-diazabicyclo[2.2.2.]octane (DABCO)and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); alkyl lithiums such asmethyl lithium, ethyl lithium and butyl lithium; and lithium alkylamides such as lithium diisopropylamide and lithium dicyclohexylamide.Example of the above quaternary onium salt include tetrabutylammoniumchloride, tetrabutylammonium bromide, tetrabutylammonium iodide,tetrabutylammonium acetate, tetrabutylphosphonium chloride,tetrabutylphosphonium bromide, cetyltrimethylammonium bromide,tetrapropylammonium bromide and benzyltriethylammonium chloride. Acombination of 18-crown-6-ether and a salt such as potassium chloride,potassium bromide, potassium iodide, cesium chloride, potassiumphenoxide, sodium phenoxide or potassium benzoate may also be used as acatalyst.

[0178] Out of these, p-toluenesulfonic acid, hydrochloric acid, sulfuricacid, sodium hydroxide, potassium t-butoxide, triethylamine, DBU,tetrabutylammonium bromide, tetrabutylphosphonium bromide and18-crown-6-ether/potassium phenoxide are preferred as a catalyst.

[0179] The amount of the catalyst is preferably 2 mols or less based on1 equivalent of the component (D) when an amino compound, alkoxymethylmelamine compound, alkoxymethyl glycoluril compound, alkoxymethylbenzoguanamine compound, alkoxymethyl urea compound or silyl halidecompound is used as the component (D).

[0180] When an epoxy compound, thiirane compound, oxetane compound,isocyanate compound, cyanate compound, oxazoline compound, oxazinecompound or other silyl compound is used as the component (D), it ispreferably 0.2 mol or less based on 1 equivalent of the component (D).

[0181] The number of equivalents of the component (D) is obtained bymultiplying the number of reactive groups contained in the component (D)by the amount (mol) of the component (D) and the number of reactivegroups is defined as follows according to the type of the component (D).amino compound: number of nitrogen atoms epoxy compound: number of epoxygroups thuirane compound: number of ethylene sulfide groups oxetanecompound: number of oxetanyl groups alkoxymethyl melamine compound,alkoxymethyl glycoluril compound, alkoxymethyl benzoguanamine compoundand alkoxymethyl urea compound: number of alkoxymethyl groups isocyanatecompound: number of isocyanate group cyanate compound: number of cyanategroups oxazoline compound: number of oxazolyl groups oxazine compound:number of oxazyl groups silyl halide compound: number of halogen atomsbonded to silicon atoms other silyl compound: number of silicon atoms

[0182] <Other Components>

[0183] The refractive index changing composition used in the presentinvention may contain other additives in limit not prejudicial to theobject of the present invention. The additives include an ultravioletlight absorber, sensitizer, surfactant, heat resistance improving agentand adhesive aid.

[0184] The above ultraviolet light absorber is a benzotriazole,salicylate, benzophenone, substituted acrylonitrile, xanthene, coumarin,flavone or chalcone. Specific examples of the ultraviolet light absorberinclude Tinubin 234 (2-(2-hydroxy-3,5-bis (α,α-dimethylbenzyl)phenyl)-2H-benzotriazole), Tinubin 571(hydroxyphenylbenzotriazole derivative) and Tinubin 1130 (condensate ofmethyl-3-(3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl)propionateand polyethylene glycol (molecular weight of 300)) (of Ciba SpecialtyChemicals), and1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, anddibenzylidene acetone.

[0185] By adding an ultraviolet light absorber, the amount of an acid orbase formed from the component (C) can be made gradually smaller as thedepth from the surface of an exposed portion of the refractive indexchanging composition of the present invention increases, which is usefulas means of forming GRIN. The amount of the ultraviolet light absorberis preferably 30 parts or less by weight, more preferably 20 parts orless by weight based on 100 parts by weight of the total of thecomponents (A) and (B).

[0186] The above sensitizeris, for example, a coumarin having asubstituent at the 3-position and/or 7-position, flavone,dibenzalacetone, dibenzalcyclohexane, chalcone, xanthene, thioxanthene,porphyrin, phthalocyanine, acridine or anthracene.

[0187] The amount of the sensitizer is preferably 30 parts or less byweight, more preferably 20 parts or less by weight based on 100 parts byweight of the total of the components god (A) and (B).

[0188] The above surfactant may be added to improve coatability, forexample, prevent striation or improve developability.

[0189] Examples of the surfactant include nonionic surfactants such aspolyoxyethylene alkyl ethers including polyoxyethylene lauryl ether,polyoxyethylene stearyl ether and polyoxyethylene oleyl ether;polyoxyethylene aryl ethers including polyoxyethylene octylphenyl etherand polyoxyethylene nonylphenyl ether; and polyethylene glycol dialkylesters including polyethylene glycol dilaurate and polyethylene glycoldistearate; fluorinated surfactants such as F Top EF301, EF303 and EF352(of Shin Akita Kasei Co., Ltd.), which are available under the TradeNames thereof, Megafac F171, F172 and F173 (of Dainippon Ink andChemicals, Inc.), Florade FC430 and FC431 (of Sumitomo 3M Limited), andAsahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105and SC-106 (of Asahi Glass Co., Ltd.); other surfactants such asorganosiloxane polymer KP341 (of Shin-Etsu Chemical Co., Ltd.) andacrylic or methacrylic acid-based (co)polymer Polyflow No. 57 and No. 95(of Kyoeisha Kagaku Co., Ltd.), which are available under the TradeNames thereof.

[0190] The amount of the surfactant is preferably 2 parts or less byweight, more preferably 1 part or less by weight based on 100 parts byweight of the total of the components (A) and (B).

[0191] The above adhesive aid may be added to improve adhesion to asubstrate and is preferably a silane coupling agent.

[0192] The above heat resistance improving agent is an unsaturatedcompound such as a polyvalent acrylate.

[0193] An antistatic agent, keeping stabilizer, halation inhibitor,anti-foaming agent, pigment and thermal generator may be further addedto the refractive index changing material used in the present inventionas required.

[0194] <Formation of Refractive Index Pattern>

[0195] In the present invention, a refractive index pattern can beformed from the above refractive index changing composition as follows,for example.

[0196] First, the refractive index changing composition is dissolved ordispersed in a solvent to prepare a composition having a solid contentof 5 to 70wt %. The composition may be filtered with a filter having apore diameter of about 0.1 to 10 μm as required before use.

[0197] Thereafter, this composition is applied to the surface of asubstrate such as a silicon wafer and prebaked to remove the solvent soas to form a coating film of the refractive index changing composition.The parts of formed coating film is then exposed to radiation through apattern mask and heated to make a refractive index difference betweenexposed and unexposed portions of the refractive index changingcomposition.

[0198] An acid or base is formed from the radiation sensitive decomposer(C) by the above exposure to act on the component (A) to decompose it.This decomposed product dissipates at the time of heating afterexposure. As a result, there exists a difference in refractive indexbetween exposed and unexposed portions.

[0199] At the time of heating, the residual components (A) and (D) whichdid not react with an acid or base react with each other to stabilizethe formed refractive index pattern.

[0200] The solvent used to prepare a solution containing the refractiveindex changing composition used in the present invention uniformlydissolves the above components (A), (B), (C), (D) and other optionallyadded additives and does not react with these components.

[0201] Examples of the solvent include alcohols such as methanol,ethanol, propanol, iso-propanol, butanol, ethylene glycol and propyleneglycol; ethers such as tetrahydrofuran; glycol ethers such as ethyleneglycol monomethyl ether and ethylene glycol monoethyl ether; ethyleneglycol alkylether acetates such as methyl cellosolve acetate and ethylcellosolve acetate; diethylene glycols such as diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycoldimethyl ether and diethylene glycol ethyl methyl ether; propyleneglycol monoalkyl ethers such as propylene glycol methyl ether, propyleneglycol ethyl ether, propylene glycol propyl ether and propylene glycolbutyl ether; propylene glycol alkyl ether acetates such as propyleneglycol methyl ether acetate, propylene glycol ethyl ether acetate,propylene glycol propyl ether acetate and propylene glycol butyl etheracetate; propylene glycol alkyl ether acetates such as propylene glycolmethyl ether propionate, propylene glycol ethyl ether propionate,propylene glycol propyl ether propionate and propylene glycol butylether propionate; aromatic hydrocarbons such as toluene and xylene;ketones such as methyl ethyl ketone, cyclohexanone and4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethylacetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate,methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate,methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate,methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl3-hydroxypropionate, butyl 3-hydroxypropionate, methyl2-hydroxy-3-methylbutanoate, methyl methoxyacetate, ethylmethoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methylethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butylethoxyacetate, methyl propoxyacetate, ethyl propoxyacetate, propylpropoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethylbutoxyacetate, propyl butoxyacetate, butyl butoxyacetate, methyl2-methoxypropionate, ethyl 2-methoxypropionate, propyl2-methoxypropionate, butyl 2-methoxypropionate, methyl2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate,butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl2-butoxypropionate, propyl 2-butoxypropionate, butyl 2-butoxypropionate,methyl 3-methoxypropionate, ethyl 3-methoxypropionate. propyl3-methoxypropionate, butyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate,butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl3-propoxypropionate, propyl 3-propoxypropionate, butyl3-propoxypropionate, methyl 3-butoxypropionate, ethyl3-butoxypropionate, propyl 3-butoxypropionate, and butyl3-butoxypropionate; and fluorine atom-containing solvents such astrifluoromethyl benzene, 1,3-bis(trifluoromethyl)benzene,hexafluorobenzene, hexafluorocyclohexane, perfluorodimethyl cyclohexane,perfluoromethyl cyclohexane, octafluorodecalin and1,1,2-trichloro-1,2,2-trifluoroethane.

[0202] Out of these solvents, alcohols, glycol ethers, ethylene glycolalkyl ether acetates, propylene glycol alkyl ether acetates, ketones,esters and diethylene glycols are preferred from the viewpoints ofsolubility, reactivity with each component and ease of forming a coatingfilm.

[0203] Further, a high-boiling solvent may be used in combination withthe above solvent. Examples of the high-boiling solvent includeN-methylformamide, N,N-dimethylformamide, N-methylformanilide,N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexyl ether, acetonyl acetone,isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzylalcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethylmaleate, γ-butyrolactone, ethylene carbonate, propylene carbonate andphenyl cellosolve acetate.

[0204] The refractive index changing composition used in the presentinvention is formed into various shapes in consideration of applicationpurpose before exposure to radiation. For example, it is formed like arod, fiber, long plate, sphere, film or lens and the present inventionis not limited to these. A commonly used method may be used to form therefractive index changing composition of the present invention. Forexample, injection molding, compression molding, blow molding,extrusion, in-case frame polymerization, shaving, drawing,heating/cooling, CVD deposition, sintering or scanning is employed. Spincoating, slitting, bar coating, solvent casting, LB, spraying, rollcoating, relief-printing or screen printing may also be used accordingto the application purpose of an optically molded product.

[0205] In this molding process, heating (to be referred to as“prebaking” hereinafter) is preferably carried out. The heatingcondition which changes according to the composition of the material ofthe present invention and the type of each additive is preferably 30 to200° C., more preferably 40 to 150° C. A hot plate or oven, or infraredradiation may be used for heating.

[0206] The radiation used for exposure is an i-ray having a wavelengthof 365 nm, h-ray having a wavelength of 404 nm, g-ray having awavelength of 436 nm, ultraviolet ray from a wide-range wavelength lightsource such as a xenon lamp, far ultraviolet ray such as KrF excimerlaser beam having a wavelength of 248 nm or ArF excimer laser beamhaving a wavelength of 193 nm, X-ray such as synchrotron radiation,charged corpuscular beam such as electron beam, visible ray or a mixturethereof. Out of these, ultraviolet radiation and visible radiation arepreferred. The illuminance which depends on the wavelength of theradiation is preferably 0.1 to 100 mW/cm² because the highest reactionefficiency is obtained. The irradiation of the radiation through apattern mask makes possible the patterning of the radiation sensitiverefractive index changing material. As for patterning accuracy which isaffected by a light source used, an optical part having a refractiveindex variation distribution with a resolution of about 0.2 μm can beproduced.

[0207] In the present invention, heating (to be referred to as“post-exposure baking (PEB)”) is preferably carried out after exposure.A similar device to the above prebaking device may be used for PEB andPEB conditions may be arbitrary. The heating temperature is preferably30 to 150° C., more preferably 30 to 130° C. Heating for stabilizationis preferably carried out continuously after PEB or separately from PEBto react the residual components (A) and (D). The heating temperaturefor stabilization is preferably 35 to 200° C., more preferably atemperature 10° C. or more higher than the PEB temperature, much morepreferably a temperature 20° C. or more higher than the PEB temperature.

[0208] Further, re-exposure may be carried out to decompose the residualcomponent (C) existent in the unexposed portion and further improve thestability of the material.

[0209] The re-exposure may be carried out by irradiating radiationhaving the same wavelength as the radiation used to change therefractive index onto the entire surface of the pattern in the sameamount.

[0210] Optionally, the stability of the material can be further improvedby heating. A similar device to the prebaking device used at the time ofmolding the material may be used for heating and the heating conditionsmay be arbitrary.

[0211] According to the present invention, the refractive index patternforming method of the present invention may also be carried out byirradiating a refractive index changing composition comprising the abovecomponents (A), (B) and (C) with radiation through a pattern mask andtreating it with a stabilizer (D).

[0212] The treatment with the stabilizer (D) is preferably carried outafter post-exposure baking.

[0213] The stabilizer (D) has the function of stabilizing the residualdecomposable compound (A) contained in the refractive index changingmaterial after exposure to provide stability to an acid or base. Thisstabilization prevents a change in refractive index and hence thedeterioration of a refractive index pattern formed by the method of thepresent invention even when it is used under the condition that lighthaving a wavelength close to the wavelength used to change therefractive index passes therethrough.

[0214] A low-boiling compound such as ammonia or triethylamine may beused as the stabilizer (D) besides the above examples.

[0215] For contact between the refractive index changing compositionafter exposure to radiation and the stabilizer (D) for stabilization, asuitable method may be employed. For instance, the component (D) andoptionally a catalyst are dissolved in a suitable solvent to becontacted to the refractive index changing composition as a solution.Alternatively, when the component (D) is liquid or gas under contactconditions, it may be 100% directly contacted to the refractive indexchanging composition.

[0216] When a solvent is used in the reaction between the abovestabilizer (D) and the component (A), the solvent preferably dissolvesthe component (D) and an optionally added catalyst and does not dissolvethe component (A). If the above solvent is selected, the surface of theobtained refractive index pattern will not be roughened.

[0217] Examples of the solvent include water; alcohols such as methanol,ethanol, iso-propanol, n-propanol, n-butanol, iso-butanol, tert-butanol,cyclohexanol, ethylene glycol, propylene glycol and diethylene glycol;ethers such as diethyl ether and tetrahydrofuran; glycol ethers such asethylene glycol monomethyl ether and ethylene glycol monoethyl ether;ethylene glycol alkyl ether acetates such as methyl cellosolve acetateand ethyl cellosolve acetate; diethylene glycols such as diethyleneglycol monomethyl ether, diethylene glycol monoethyl ether anddiethylene glycol dimethyl ether; propylene glycol monoalkyl ethers suchas propylene glycol methyl ether and propylene glycol ethyl ether;propylene glycol alkyl ether acetates such as propylene glycol methylether acetate and propylene glycol ethyl ether acetate; propylene glycolalkyl ether acetates such as propylene glycol methyl ether propionate,propylene glycol ethyl ether propionate, propylene glycol propyl etherpropionate and propylene glycol butyl ether propionate; aromatichydrocarbons such as toluene and xylene; aliphatic hydrocarbons such asn-hexane, n-heptane and n-octane; ketones such as methyl ethyl ketone,cyclohexanone, methyl isobutyl ketone, methylamyl ketone and4-hydroxy-4-methyl-2-pentanone; esters such as ethyl acetate, propylacetate, butyl acetate, ethyl 2-hydroxypropionate, methyl2-hydroxy-2-methylpropionate, ethyl hydroxyacetate, butylhydroxyacetate, ethyl lactate, propyl lactate, butyl lactate, methyl3-hydroxypropionate, methyl 2-hydroxy-3-methylbutanoate, ethylmethoxyacetate, butyl methoxyacetate, ethyl 2-methoxypropionate, butyl2-methoxypropionate, butyl 2-ethoxypropionate, butyl 2-butoxypropionate,butyl 3-methoxypropionate, butyl 3-ethoxypropionate, butyl3-propoxypropionate and butyl 3-butoxypropionate; and fluorineatom-containing solvents such as trifluoromethylbenzene,1,3-bis(trifluoromethyl)benzene, hexafluorobenzene,hexafluorocyclohexane, perfluorodimethylcyclohexane,perfluoromethylcyclohexane, octafluorodecalin and1,1,2-trichloro-1,2,2-trifluoroethane.

[0218] Out of these solvents, water, alcohols, glycol ethers, ethyleneglycol alkyl ether acetates and fluorine atom-containing solvents arepreferred.

[0219] The reaction temperature for carrying out a reaction between thestabilizer (D) and the residual decomposable compound (A) is generally 0to 130° C., and the reaction time is generally 10 seconds to 1 hour.

[0220] Further, re-exposure may be carried out to decompose the residualcomponent (C) existent in the unexposed portion and further improve thestability of the material.

[0221] As for what is not described of the refractive index patternforming method including the above stabilization, it should beunderstood that the above description of the refractive index patternforming method is applied directly or with modifications obvious topeople having ordinary skill in the art.

[0222] Further, according to the present invention, the refractive indexpattern forming method of the present invention may also be carried outby irradiating the refractive index changing composition comprising theabove components (A), (B) and (C) with radiation through a pattern andheating to decompose the decomposable compound (A) of an unexposedportion.

[0223] The above heating is preferably carried out at a temperature 10°C. or more higher than the PEB temperature, for example, preferably 170°C. or more, more preferably 200° C. or more.

[0224] By the above heating, the residual decomposable compound (A)existent in the unexposed portion is removed by decomposition orsublimation and preferably does not form pores substantially.

[0225] As for what is not described of the above refractive indexpattern forming method when the component (D) is not contained, itshould be understood that related items out of the above description ofthe pattern forming method are applied directly or with modificationsobvious to people having ordinary skill in the art.

[0226] In the refractive index pattern of the present invention formedby any one of the above various methods, the refractive index of anexposed portion (first region) is preferably smaller than that of anunexposed portion (second region). This difference can be adjusted to adesired value by controlling the types and contents of the components(A) and (B) contained in the refractive index changing composition usedin the present invention. For example, the largest value of refractiveindex difference can be set to a value larger than 0.02.

[0227] The refractive index pattern of the present invention has poresor do not have any pores in the exposed portion.

[0228] When the exposed portion has pores, the porosity is preferably 10to 99.9%, more preferably 15 to 99.9%, particularly preferably 20 to99.9%.

[0229] The elastic moduli of the exposed portion and unexposed portionare preferably 0.3 GPa or more and 1 GPa or more, more preferably 0.5GPa or more and 3 GPa or more, respectively.

[0230] The elastic modulus of the exposed portion is preferably smallerthan that of the unexposed portion.

[0231] Since the refractive index pattern of the present invention doesnot deteriorate without a change in refractive index even when it isused under the condition that light having a wavelength close to thewavelength used to change the refractive index passes therethrough asdescribed above, it is extremely useful as an optical material for usein the optoelectronic and display fields.

[0232] As the refractive index pattern of the present invention has asufficiently large refractive index difference and the formed refractiveindex difference is stable to light and heat, it is extremely useful asan optical material for use in the optoelectronic and display fields.The refractive index pattern of the present invention may be used inoptical parts such as other photoarrays, lenses, photocouplers,photointerruptors, polarization beam splitters, holograms, single-modeand multi-mode optical fibers, bundle fibers, light guides, single-core,multi-core and photoelectric coupling optical connectors, opticalisolators, polarizers, optical sensors such as photodiodes,phototransistors, photo-ICs, CCD image sensors, CMOS image sensors,optical fiber sensors and optical fiber gyros, optical disks such as CD,LD, PD and DVD, optical switches, waveguides, optical touch panels,diffraction gratings, optical guide plates, optical diffusers,anti-reflectors and optical sealers.

[0233] <Method of Producing Optical Parts>

[0234] The photosensitive refractive index changing composition isformed into various shapes in consideration of application purposebefore exposure to radiation.

[0235] For example, it is formed like a rod, fiber, long plate, sphere,film or lens and the present invention is not limited to these. Acommonly used method may be used to form the refractive index changingcomposition, as exemplified by injection molding, compression molding,blow molding, extrusion, in-case frame polymerization, shaving, drawing,heating/cooling, CVD deposition, sintering or scanning. Spin coating,slitting, bar coating, solvent casting, LB, spraying, roll coating,relief-printing or screen printing may also be used according to theapplication purpose of an optically molded product.

[0236] The Light used for exposure is an i-ray having a wavelength of365 nm, h-ray having a wavelength of 404 nm, g-ray having a wavelengthof 436 nm, ultraviolet ray from a wide-range wavelength light sourcesuch as a xenon lamp, far ultraviolet ray such as KrF excimer laser beamhaving a wavelength of 248 nm or ArF excimer laser beam having awavelength of 193 nm, X-ray such as synchrotron radiation, chargedcorpuscular beam such as electron beam, visible a radiation or a mixturethereof. Out of these, ultraviolet radiation and visible radiation arepreferred. The illuminance which depends on the wavelength of theradiation is preferably 0.1 to 100 mW/cm² because the highest reactionefficiency is obtained. The irradiation of the radiation through apattern mask makes possible the patterning of the radiation sensitiverefractive index changing material. As for patterning accuracy which isaffected by a light source used, an optical part having a refractiveindex variation distribution with a resolution of about 0.2 μm can beproduced.

[0237] In the present invention, heating (to be referred to as“post-exposure baking (PEB)” hereinafter) is preferably carried outafter exposure. The heating condition which changes according to thecomposition of the material of the present invention and the type ofeach additive is preferably 30to200° C., more preferably 40 to 150° C. Ahot plate or oven, or infrared radiation may be used for heating.

[0238] The difference between the maximum refractive index and theminimum refractive index in the refractive index distribution of anoptical part of the present invention can be set to a desired valueaccording to application purpose as described above. It can be set to0.02 or more, optionally 0.03 or more, 0.05 or more, or 0.08 or more.

[0239] As specific examples, the methods of forming an optical fiber,lens, optical waveguide, diffraction grating, hologram element andrecording medium will be described in detail.

[0240] <Method of Forming an Optical Fiber>

[0241] An optical fiber may be formed by a suitable method, for example,the following method.

[0242] A photosensitive refractive index changing composition forforming an optical fiber may be dissolved in a suitable solvent beforeuse. The solvent used may be a solvent having a boiling point of 50 to200° C. and the solid content of the obtained solution may be 50 to 80%.This solution is used as a fiber stock solution, defoamed, stretched byheating, exposed to a laser beam and extruded to form a fiber. The porediameter may be 0.1 to 1.0 mm and the stretching speed may be 0.1 to1,000 m/min.

[0243] The fiber formed as described above is then exposed to lightuniformly from therearound toward the center using a ring light sourcetogether with an optical fiber or reflector and post exposured baked toform the optical fiber of the present invention. The PEB temperature maybe 50 to 200° C. and the baking time may be 1 second to 30 minutes. Asuitable heating source such as an infrared lamp may be used as theheating source.

[0244] An GI type optical fiber having such a distribution thatrefractive index decreases in a parabolic manner from the center axis tothe periphery can be formed by adjusting the amount of exposure,selecting a wavelength and using an ultraviolet light absorber.

[0245] The above fiber stretching device, exposure device and heatingdevice may be arranged side by side. Thereby, an GI type optical fibercan be produced continuously.

[0246] <Method of Forming a Lens>

[0247] The lens of the present invention may be formed by a suitablemethod, for example, the following method.

[0248] (1) Method of Forming a GRIN Lens having Concave Lens Power

[0249] A photosensitive refractive index changing composition used forthe formation of a lens can be dissolved in a suitable solvent beforeuse. The solvent used may be a solvent having a boiling point of 50 to200° C. and the solid content of the obtained solution may be 50 to 80%.This solution is formed into a disk having a desired shape by hotpressing or the like.

[0250] Thereafter, the disk is exposed to light in such a manner thatthe amount of exposure is large at the center portion of the disk anddecreases toward the periphery of the disk and then post exposured bakedto form a GRIN lens having concave lens power. The exposure device issuch as shown in FIG. 1. The diaphragm 2 which can be opened or closedis installed in front of a disk sample 1 of the exposure device of FIG.1, only parallel rays from the above light source are irradiated ontothe sample by gradually opening the closed diaphragm 2, and the shutterspeed is adjusted such that the diaphragm 2 is fully opened in 1 secondto 5 minutes to achieve the above exposure state.

[0251] The post exposured baking conditions include a temperature of 50to 200° C. and a time of I second to 30 minutes.

[0252] (2) Method of Forming a GRIN Lens Having Convex Lens Power

[0253] A similar disk sample to that described above (1) is exposed tolight in such a manner that the amount of exposure is large at theperiphery of the disk and decreases toward the center of the disk andthen post exposured baked to form a GRIN lens having convex lens power.

[0254] This exposure state can be obtained by inputting light uniformlyfrom the side only while the top and bottom portions of the cylinder areshielded from light. An optical fiber or reflector may be used foruniform exposure from the side.

[0255] The same PEB conditions as (1) above may be employed.

[0256] <Method of Forming an Optical Waveguide>

[0257] The optical waveguide of the present invention may be formed by asuitable method, for example, the following method.

[0258] A photosensitive refractive index changing composition forforming an optical waveguide may be dissolved in a suitable solventbefore use (solution A). The solvent used may be a solvent having aboiling point of 50 to 200° C. and the solid content of the obtainedsolution may be 20 to 60%.

[0259] Separately from this solution, a composition solution comprisingthe component (B) and a thermal acid generator and/or a photo acidgenerator is prepared (solution B). The solid content of this solutionmay be 20 to 60% and a solvent having a boiling point of 50 to 200° C.may be used.

[0260] The solution B is first applied to a suitable substrate such as asilicon substrate or glass substrate and then the solvent is removed toform a coating film as thick as 1 to 50 μm. This coating film serves asa lower clad layer. Spin coating or slit coating may be employed toapply the solution B and heating may be carried out at 50 to 150° C. for1 to 30 minutes to remove the solvent.

[0261] Thereafter, the solution A is applied to the lower clad layerformed as described above and then the solvent is removed to form anintermediate layer as thick as 1 to 50 μm. The coating method and theremoval of the solvent may be the same as described above.

[0262] Subsequently, the intermediate layer is exposed to light througha photomask for shielding the core portion of a waveguide pattern fromlight and post exposured baked. The unexposed portion serves as a coreportion and the exposed portion serves as a side clad layer. The postexposured baking conditions include a temperature of 50 to 200° C. and atime of 1 second to 30 minutes.

[0263] The solution B is applied to the above intermediate layer againand then the solvent is removed to form an upper clad layer as thick as1 to 50 μm, thereby making it possible to form an optical waveguide.Since the obtained optical waveguide contains the thermal acid generatorin the upper and lower clad layers, an acid slightly formed is diffusedat the interfaces between the core layer and the lower clad layer andbetween the core layer and the upper clad layer. Thereby, the interfacesbetween the core layer and the clad layers can take such a structurethat the refractive index changes gradually in the upper, side and lowerportions with the result that a GI type optical waveguide is obtained.

[0264] <Method of Forming a Recording Medium>

[0265] The recording medium of the present invention may be formed by asuitable method, for example, the following method.

[0266] A photosensitive refractive index changing composition forforming a recording medium may be dissolved in a suitable solvent beforeuse. The solvent used may be a solvent having a boiling point of 50 to200° C., and the solid content of the obtained solution may be 5 to 50%.

[0267] This solution is applied to a flat plastic substrate having ametal film such as an aluminum film having a thickness of about 60 nmand then the solvent is removed to form a coating film as thick as 0.1to 10 μm. Spin coating or slit coating may be used to apply thesolution, and the solvent can be removed by heating at 50 to 150° C. for1 to 30 minutes.

[0268] Thereafter, this coating film is exposed to light through aphotomask having a track pick of 1.6 μm at a pitch width of 0.2 to 0.5μm and post exposured baked to form an optical recording medium. Thepost exposured baking conditions include a temperature of 50 to 200° C.and a time of 1 second to 30 minutes.

[0269] <Method of Forming a Diffraction Grating>

[0270] The diffraction grating of the present invention may be formed bya suitable method, for example, the following method.

[0271] A photosensitive refractive index changing composition forforming a diffraction grating may be dissolved in a suitable solventbefore use. The solvent used may be a solvent having a boiling point of50 to 200° C., and the solid content of the obtained solution may be 20to 60%.

[0272] This solution is applied to the surface of a suitable substratesuch as a glass substrate and then the solvent is removed to form a thincoating film as thick as 1 to 50 μm. Spin coating or slit coating may beused to apply the solution, and the solvent can be removed by heating at50 to 150° C. for 1 to 30 minutes.

[0273] This coating film is exposed to light in a slit form and postexposured baked to form a diffraction grating. To irradiate slit-formlight, for example, the method shown in FIG. 2 may be employed. FIG. 2shows that parallel rays reflected by a reflector placed obliquely areirradiated onto a coating film. The coating film is exposed to aninterference pattern formed by direct rays and reflected rays. Thesample is moved in a direction shown by an arrow in the figure at aspeed of 0.1 to 100 μm/min while it is illuminated to form a diffractiongrating having a desired cycle of 0.3 μm or more. A fine refractiveindex distribution can be provided by this method.

[0274] Another method of irradiating slit-form light is to irradiate thecoating film formed as described above with a plurality of radial raysfrom different directions for interference or to irradiate light throughslits. In either method, a diffraction grating having a desired cyclecan be formed by changing the input angle of light or the angle of amirror.

[0275] The above post exposured baking conditions include a temperatureof 50 to 200° C. and a time of 1 second to 30 minutes.

[0276] <Method of Forming a Hologram Element>

[0277] The hologram element of the present invention may be formed by asuitable method, for example, the following method.

[0278] A photosensitive refractive index changing composition forforming a hologram element may be dissolved in a suitable solvent beforeuse. The solvent used may be a solvent having a boiling point of 50 to200° C. and the solid content of the obtained solution may be 20 to 60%.

[0279] This solution is applied to a suitable substrate such as a glasssubstrate and then the solvent is removed to form a thin film as thickas 1 to 50 μm. Spin coating or slit coating may be employed to apply thesolution. The solvent can be removed by heating at 50 to 150° C. for 1to 30 minutes.

[0280] This coating is irradiated with an interference pattern and postexposured baked to form a recording medium (hologram) for holography.That is, signal light passing through a substance to be recorded andreference light directly obtained from the same light source areinterfered with each other and irradiated onto the coating film tochange the refractive index, thereby making it possible to record animage of the substance on the coating film.

[0281] The above post exposured baking conditions include a temperatureof 50 to 200° C. and a time of 1 second to 30 minutes.

EXAMPLES

[0282] The following examples are provided for the purpose of furtherillustrating the present invention but are in no way to be taken aslimiting.

[0283] The weight average molecular weight in terms of polystyrene of apolymer was measured using the GPC CHROMATOGRAPH SYSTEM-21 of ShowaDenko K.K.

[0284] Synthesis Examples of Component (A)

Synthesis Example 1

[0285] 50 parts by weight of o-phthalaldehyde as a monomer and 500 partsby weight of tetrahydrofuran were fed to a 1-liter flask whose insidehad been substituted with nitrogen and cooled to −78° C. 1.0 part byweight of an n-hexane solution of n-butyl lithium (1.5 mols/l) was addedto this flask and stirred under cooling at −78° C. for 48 hours in anitrogen atmosphere.

[0286] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The reaction solution was concentratedto 100 ml by heating at 60° C. under reduced pressure and injected into5 liters of ion exchange water in 10 minutes. The precipitate wasre-dissolved in 50 parts by weight of tetrahydrofuran, purified byre-precipitation with5liters of ion exchange water and vacuum dried at50° C. to obtain 45 parts by weight of a compound (A-1). The weightaverage molecular weight of the obtained compound was 26,000.

Synthesis Example 2

[0287] 45 parts by weight of o-phthalaldehyde, 5 parts by weight ofbenzaldehyde as a monomer and 500 parts by weight of tetrahydrofuranwere fed to a 1-liter flask whose inside had been substituted withnitrogen and cooled to −78° C. 1.0 part by weight of an n-hexanesolution of n-butyl lithium (1.5 mols/l) was added to this flask andstirred under cooling at −78° C. for 48 hours in a nitrogen atmosphere.

[0288] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The whole reaction solution wasconcentrated to 100 ml by heating at 60° C. under reduced pressure andcontinuously injected into 5 liters of ion exchange water in 10 minutes.The precipitate was re-dissolved in 50 parts by weight oftetrahydrofuran, purified by re-precipitation with 5 liters of ionexchange water and vacuum dried at 50° C. to obtain 43 parts by weightof a compound (A-2). The weight average molecular weight of the obtainedcompound was 15,000.

Synthesis Example 3

[0289] 45 parts by weight of o-phthalaldehyde and 5 parts by weight ofglutaraldehyde as monomers, and 500 parts by weight of tetrahydrofuranwere fed to a 1-liter flask whose inside had been substituted withnitrogen and cooled to −78° C. 1.0 part by weight of an n-hexanesolution of n-butyl lithium (1.5 mols/l) was added to this flask andstirred under cooling at −78° C. for 48 hours in a nitrogen atmosphere.

[0290] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The whole reaction solution wasconcentrated to 100 ml by heating at 60° C. under reduced pressure andcontinuously injected into 5 liters of ion exchange water in 10 minutes.The precipitate was re-dissolved in 50 parts by weight oftetrahydrofuran, purified by re-precipitation with 5 liters of ionexchange water and vacuum dried at 50° C. to obtain 45 parts by weightof a compound (A-3). The weight average molecular weight of the obtainedcompound was 20,000.

Synthesis Example 4

[0291] 25 parts by weight of 4-chloro-o-phthalaldehyde as a monomer and500 parts by weight of methylene chloride were fed to a 1-liter flaskwhose inside had been substituted with nitrogen and cooled to −78° C.0.1 part by weight of a boron trifluoride ether complex was added tothis flask and stirred under cooling at −78° C. for 48 hours in anitrogen atmosphere.

[0292] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The whole reaction solution wasconcentrated to 50 ml by heating at 60° C. under reduced pressure andcontinuously injected into 3 liters of ion exchange water in 5 minutes.The precipitate was re-dissolved in 30 parts by weight oftetrahydrofuran, purified by re-precipitation with 3 liters of ionexchange water and vacuum dried at 50° C. to obtain 46 parts by weightof a compound (A-4). The weight average molecular weight of the obtainedcompound was 48,000.

Synthesis Example 5

[0293] 25 parts by weight of 4-bromo-o-phthalaldehyde as a monomer and500 parts by weight of methylene chloride were fed to a 1-liter flaskwhose inside had been substituted with nitrogen and cooled to −78° C.0.1 part by weight of a boron trifluoride ether complex was added tothis flask and stirred under cooling at −78° C. for 48 hours in anitrogen atmosphere.

[0294] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The whole reaction solution wasconcentrated to 50 ml by heating at 60° C. under reduced pressure andcontinuously injected into 3 liters of ion exchange water in 5 minutes.The precipitate was re-dissolved in 30 parts by weight oftetrahydrofuran, purified by re-precipitation with 3 liters of ionexchange water and vacuum dried at 50° C. to obtain 47 parts by weightof a compound (A-5). The weight average molecular weight of the obtainedcompound was 53,000.

Synthesis Example 6

[0295] 50 parts by weight of o-phthalaldehyde as a monomer and 500 partsby weight of tetrahydrofuran were fed to a 1-liter flask whose insidehad been substituted with nitrogen and cooled to −78° C. 0.2 part byweight of an n-hexane solution of n-butyl lithium (1.5 mols/l) was addedto this flask and stirred under cooling at −78° C. for 48 hours in anitrogen atmosphere.

[0296] 0.8 part by weight of acetic anhydride and 0.6 part by weight ofpyridine were added to the obtained reaction solution under cooling andstirred at −78° C. for 2 hours. The whole reaction solution wasconcentrated to 100 ml by heating at 60° C. under reduced pressure andcontinuously injected into 5 liters of ion exchange water in 10 minutes.The precipitate was re-dissolved in 50 parts by weight oftetrahydrofuran, purified by re-precipitation with 5 liters of ionexchange water and vacuum dried at 50° C. to obtain 45 g of a compound(A-6). The weight average molecular weight of the obtained compound was110,000.

Synthesis Example 7

[0297] 33.05 g of 1,4-benzenethiol and 66.06 g of1,4-di(2-nitrovinyl)benzene were dissolved in 100 g ofN-methylpyrrolidone in a 500-ml three-necked flask in an argonatmosphere. A solution obtained by dissolving 1.55 g ofN-methylmorpholine in 10 g of N-methylpyrrolidone was injected into theabove solution under cooling with ice and agitation in 1 hour. After theend of injection, the reaction solution was left at room temperature tocarry out polymerization for 24 hours. After the end of polymerization,the resultant polymer was purified by carrying on re-precipitation twicewith tetrahydrofuran-methanol.

[0298] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 72.80 g of a compound (A-7). The weightaverage molecular weight of the obtained compound was 5,800.

Synthesis Example 8

[0299] 49.84 g of terephthalic acid chloride was dissolved in 150 ml ofchloroform in a 500-ml three-necked flask in an argon atmosphere. Asolution obtained by dissolving 33.05 g of 1,4-benzenethiol and 16.83 gof potassium hydroxide in 150 ml of ion exchange water was added to theabove solution and stirred to carry out interfacial polycondensation.After 6 hours of the reaction, the resutant polymer was purified bycarrying on re-precipitation twice with tetrahydrofuran-methanol.

[0300] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 61.28 g of a compound (A-8). The weightaverage molecular weight of the obtained compound was 27,600.

Synthesis Example 9

[0301] 33.05 g of 1,4-benzenethiol, 48.04 g of p-phenylene diisocyanateand 0.12 g of dibutyltin dichloride as a catalyst were dissolved in 200g of dimethyl sulfoxide in a 500-ml three-necked flask in an argonatmosphere. After the end of injection, the reaction solution was heatedat 60° C. to carry out polymerization for 24 hours. After the end ofpolymerization, the resultant polymer was purified by carrying onre-precipitation twice with tetrahydrofuran-methanol. The precipitatedpolymer was separated by filtration and vacuum dried at 50° C. to obtain66.50 g of a compound (A-9). The weight average molecular weight of theobtained compound was 15,000.

Synthesis Example 10

[0302] 92.42 g of 4-nitro-1,3-phenylene dichloroformate was dissolved in400 ml of chloroform in a 1-liter three-necked flask in an argonatmosphere. A solution obtained by dissolving 33.05 g of1,4-benzenethiol and 16.83 g of potassium hydroxide in 200 ml of ionexchange water was added to the above solution and stirred to carry outinterfacial polycondensation. After 6 hours of the reaction, theresultant polymer was purified by carrying on re-precipitation twicewith tetrahydrofuran-methanol.

[0303] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 83.61 g of a compound (A-10). The weightaverage molecular weight of the obtained compound was 32,000.

Synthesis Example 11

[0304] 49.84 g of terephthalic acid and 57.34 g of phenylmethyldichlorosilane were dissolved in 200 g of N-methylpyrrolidone in a500-ml three-necked flask in an argon atmosphere. A solution obtained bydissolving 23.73 g of pyridine in 50 g of N-methylpyrrolidone wasinjected into the above solution under agitation and cooling with ice in1 hour. After the end of injection, the reaction solution was heated at60° C. to carry out polymerization for 24 hours. After the end ofpolymerization, the reaction solution was poured into 2 liters ofmethanol for precipitation and the precipitate was re-dissolved in 200ml of N-methylpyrrolidone and injected into 2 liters of methanol tocarry out purification by re-precipitation.

[0305] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 70.80 g of a compound (A-11). The weightaverage molecular weight of the obtained compound was 26,000.

Synthesis Example 12

[0306] 45.66 g of benzaldehyde dimethyl acetal and 42.04 g ofmethoxyhydroquinone were dissolved in 100 g of diethylene glycol ethylmethyl ether in a 500-ml three-necked flask in an argon atmosphere. Asolution obtained by dissolving 0.06 g of p-toluenesulfonic acid in 10 gof diethylene glycol ethyl methyl ether was added to the above solutionand stirred to carry out polymerization at 100° C. for 8 hours and thenat 130° C. for 1 hour. The polymerization was carried out while methanolformed by the reaction was distilled off under reduced pressure.

[0307] After the end of polymerization, the reaction solution was pouredinto 2 liters of methanol for precipitation and the precipitate wasre-dissolved in 100 ml of diethylene glycol ethyl methyl ether andinjected into 2 liters of methanol to carry out purification byre-precipitation. The precipitated polymer was separated by filtrationand vacuum dried at 50° C. to obtain 47.93 g of a compound (A-12). Theweight average molecular weight of the obtained compound was 5,800.

Synthesis Example 13

[0308] 49.84 g of terephthalic acid and 57.34 g of phenylmethyldichlorosilane were dissolved in 200 g of N-methylpyrrolidone in a500-ml three-necked flask in an argon atmosphere. A solution obtained bydissolving 47.46 g of pyridine in 50 g of N-methylpyrrolidone wasinjected into the above solution under agitation and cooling with ice in1 hour. After the end of injection, the reaction solution was heated at60° C. to carry out polymerization for 24 hours. After the end ofpolymerization, the reaction solution was poured into 2 liters ofmethanol for precipitation and the precipitate was re-dissolved in 200ml of N-methylpyrrolidone and injected into 2 liters of methanol tocarry out purification by re-precipitation.

[0309] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 80.01 g of a compound (A-13). The weightaverage molecular weight of the obtained compound was 31,200.

Synthesis Example 14

[0310] 61.51 g of terephthalic acid chloride was dissolved in 150 ml ofchloroform in a 500-ml three-necked flask in an argon atmosphere. Asolution obtained by dissolving 33.05 g of 1,4-benzenethiol and 33.66 gof potassium hydroxide in 150 ml of ion exchange water was added to theabove solution and stirred to carry out interfacial polycondensation.After 6 hours of the reaction, the resultant polymer was purified bycarrying on re-precipitation twice with tetrahydrofuran-methanol.

[0311] The precipitated polymer was separated by filtration and vacuumdried at 50° C. to obtain 75.98 g of a compound (A-14). The weightaverage molecular weight of the obtained compound was 33,600.

Synthesis Example 15

[0312] 50 g of o-phthalaldehyde as a monomer and 500 g oftetrahydrofuran were fed to a 1-liter flask whose inside had beensubstituted with nitrogen and cooled to −78° C. 41.83 g of tert-butoxypotassium was added to the above solution and stirred under cooling at−78° C. for 48 hours in a nitrogen atmosphere.

[0313] 45.67 g of acetic anhydride and 35.38 g of pyridine were added tothe obtained reaction solution under cooling and stirred at −78° C. for2 hours. The reaction solution was concentrated to 100 ml by heating at60° C., dissolved in 1 liter of ethyl acetate, washed with ion exchangewater three times, and vacuum dried at 50° C. after the concentration ofethyl acetate to obtain 45 g of a compound (A-15). The initiator/monomerratio of the obtained compound (A-15) was 1:1 based on the integralratio of protons derived from 1.2 to 1.3 ppm of a tert-butyl group andprotons derived from 7.2 to 7.7 ppm of an aromatic group measured by¹H-NMR.

Synthesis Example 16

[0314] 49.84 g of terephthalic acid chloride was dissolved in 150 ml ofchloroform in a 500-ml three-necked flask in an argon atmosphere. Asolution obtained by dissolving 33.05 g of 1,4-benzenethiol and 16.83 gof potassium hydroxide in 150 ml of ion exchange water was added to theabove solution and stirred to carry out interfacial polycondensation.After 4 hours of the reaction, the resultant polymer was purified bycarrying on re-precipitation twice with tetrahydrofuran-methanol.

[0315] The precipitated compound was separated by filtration and vacuumdried at 50° C. to obtain 56.55 g of a compound (A-16). The weightaverage molecular weight of the obtained compound was 7,600.

Synthesis Examples of Component (B) Synthesis Example 1

[0316] 15.22 g of tetramethoxysilane and 27.24 g ofmethyltrimethoxysilane were dissolved in 100 g of ethylene glycol ethylmethyl ether in a 1-liter three-necked flask and the obtained mixedsolution was heated at 60° C. under stirring by a magnetic stirrer. 5.20g of ion exchange water was continuously added to the mixed solution in1 hour. After 4 hours of a reaction at 60° C., the obtained reactionsolution was cooled to room temperature. Thereafter, 9.20 g of methanolwhich was a reaction by-product was distilled off under reduced pressurefrom the reaction solution. The solid content of the solution of theobtained polymer (B-1) was 33.2% and the weight average molecular weightof the polymer was 2,200.

Synthesis Example 2

[0317] After the inside of a 1.5-liter stainless steel autoclaveequipped with an electro magnetic stirrer was fully substituted bynitrogen gas, 500 g of ethyl acetate, 57.2 g of ethylvinyl ether (EVE),10.2 g of hydroxybutyl vinyl ether (HBVE) and 3 g of lauroyl peroxidewere fed to the autoclave and cooled to −50° C. with dry ice andmethanol, and the oxygen of the system was removed with nitrogen gasagain. 146 g of hexafluoropropylene (HFP) was then fed and thetemperature began to be elevated. The pressure when the insidetemperature of the autoclave reached 60° C. was 5.3 kgf/cm². Thereafter,the reaction was continued at 60° C. for 20 hours under agitation andthe autoclave was cooled with water when the pressure dropped to 1.5kgf/cm² to stop the reaction. After the temperature reached roomtemperature, unreacted monomers were discharged and the autoclave wasopened to obtain a polymer solution having a solid content of 28.1%. Theobtained polymer solution was injected into methanol to precipitate apolymer which was then washed with methanol and vacuum dried at 50° C.to obtain 193 g of a fluorine-containing copolymer. The weight averagemolecular weight of the obtained polymer (B-2) was 17,000.

Synthesis Example 3

[0318] 8 g of 2,2′-azobis(2,4-dimethylvaleronitrile) and 200 g ofdiethylene glycol dimethyl ether were fed to a 500-ml three-neckedflask. Subsequently, 20 g of methacrylic acid, 30 g of glycidylmethacrylate and 50 g of pentafluoroethyl methacrylate were fed to theflask, the inside of the flask was substituted with nitrogen, andstirring was started gently. The temperature of the solution waselevated to 70° C. and maintained at that temperature for 3 hours toobtain a solution of a polymer (B-3). The solid content of the obtainedpolymer solution was 31.0% and the weight average molecular weight ofthe polymer was 12,000.

Synthesis Example 4

[0319] 50 g of methyltrimethoxysilane was fed to a 1-liter three-neckedflask and 100 g of 1-ethoxy-2-propanol was added and dissolved in themethyltrimethoxysilane, and the obtained mixed solution was heated at60° C. under stirring with a magnetic stirrer. 19.85 g of ion exchangewater was continuously added to this in 1 hour. A reaction was carriedout at 60° C. for 4 hours, and the obtained reaction solution was cooledto room temperature.

[0320] Thereafter, methanol which was a reaction by-product wasdistilled off from the reaction solution under reduced pressure and thereaction solution was concentrated to a solid content of 20 wt % toobtain a solution containing a compound (B-4). The weight averagemolecular weight of the compound (B-4) was 8,000.

Example 1

[0321] 40 parts by weight of the compound (A-1) as the component (A), 60parts by weight of a co-condensate (molecular weight of 2,000) of amixture of methyltrimethoxysilane and tetramethoxysilane (weight ratioof 55:5) as the component (B) and 1 part by weight of 2-(4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine as thecomponent (C) were dissolved in diethylene glycol ethyl methyl ether toa total solids content of 20 wt %, and the resulting solution wasfiltered with a membrane filter having a pore diameter of 0.2 μm toprepare a solution containing a photosensitive refractive index changingcomposition.

[0322] <Formation of a Coating Film>

[0323] The above solution was applied to a silicon substrate with aspinner and prebaked on a hot plate at 90° C. for 2 minutes to form a1.0 μm thick coating film.

[0324] <Exposure>

[0325] The obtained coating film was exposed to 20 mJ/cm² of radiationat the optimum focusing depth with the NSR1505i6A reduction projectionexposure device (of Nikon Corporation, NA=0.45,λ=365 nm) to make arefractive index difference between exposed and unexposed portions ofthe refractive index changing composition. Then, the coating film wasapplied to post exposured baked on a hot plate at 120° C. for 2 minutes.

[0326] <Measurement of Refractive Index>

[0327] The refractive indices of exposed and unexposed portions on thesilicon substrate at room temperature were measured at 633 nm with theAuto EL IV NIR III ellipsometer (of Rudolf Research Co., Ltd.). Theresults are shown in Table 1.

[0328] <Evaluation of Transparency>

[0329] A glass substrate coated with a photosensitive refractive indexchanging composition was obtained in the same manner as described aboveexcept that the Corning 1737 (of Corning Co., Ltd.) glass substrate wasused in place of the silicon substrate.

[0330] Thereafter, the transmission of the obtained glass substrate wasmeasured at a wavelength of 400 to 800 nm with the 150-20 double beamspectrophotometer (of Hitachi, Ltd.). It can be said that when theminimum transmission exceeds 95%, the transmission is satisfactory andwhen the minimum transmission is 95% or less, the transmission isunsatisfactory. The results are shown in Table 1.

Example 2

[0331] The procedure of Example 1 was repeated except that the amount ofexposure was changed to 300 mJ/cm² to evaluate refractive index andtransparency. The results are shown in Table 1.

Example 3

[0332] Evaluations were carried out in the same manner as in Example 1except that 70 parts by weight of the compound (A-1) was used as thecomponent (A) and 30 parts by weight of a condensate ofmethyltrimethoxysilane (molecular weight of 2,000) was used as thecomponent (B). The results are shown in Table 1.

Example 4

[0333] Evaluations were carried out in the same manner as in Example 1except that 15 parts by weight of the compound (A-1) was used as thecomponent (A) and 85 parts by weight of a condensate ofmethyltrimethoxysilane (molecular weight of 2,000) was used as thecomponent (B). The results are shown in Table 1.

Example 5

[0334] Evaluations were carried out in the same manner as in Example 1except that 40 parts by weight of the compound (A-2) was used as thecomponent (A). The results are shown in Table 1.

Example 6

[0335] Evaluations were carried out in the same manner as in Example 1except that 40 parts by weight of the compound (A-3) was used as thecomponent (A). The results are shown in Table 1.

Example 7

[0336] Evaluations were carried out in the same manner as in Example 1except that 40 parts by weight of the compound (A-4) was used as thecomponent (A). The results are shown in Table 1.

Example 8

[0337] Evaluations were carried out in the same manner as in Example 1except that 40 parts by weight of the compound (A-5) was used as thecomponent (A). The results are shown in Table 1

Example 9

[0338] Evaluations were carried out in the same manner as in Example 1except that 1 part by weight of 4-phenylthiophenyldiphenylsulfoniumtrifluoromethanesulfonate was used as the component (C). The results areshown in Table 1.

Example 10

[0339] Evaluations were carried out in the same manner as in Example 1except that 1 part by weight of diphenyliodonium trifluoroacetate wasused as the component (C). The results are shown in Table 1. TABLE 1transparency amount of refractive index exposed unexposed exposureexposed unexposed portion portion mJ/cm² portion portion (%) (%) Ex. 120 1.42 1.52 99.3 99.0 Ex. 2 300  1.42 1.52 99.3 99.0 Ex. 3 20 1.42 1.5599.5 98.6 Ex. 4 20 1.42 1.47 99.2 99.1 Ex. 5 20 1.42 1.52 99.3 99.1 Ex.6 20 1.42 1.51 99.3 99.2 Ex. 7 20 1.42 1.53 99.3 99.0 Ex. 8 20 1.42 1.5699.3 98.6 Ex. 9 20 1.42 1.52 99.3 99.0 Ex. 10 20 1.42 1.52 99.3 99.0

Example 11

[0340] 50 parts by weight of the compound (A-7) as the component (A), 50parts by weight of the polymer (B-1) as the component (B) and 5 parts byweight of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one asthe component (C) were dissolved in diethylene glycol ethyl methyl etherto a total solids content of 20% and the resulting solution was filteredwith a membrane filter having a pore diameter of 0.2 μm to prepare acomposition solution.

[0341] The formation of a coating film, the measurement of refractiveindex and the evaluation of transparency were carried out in the samemanner as in Example 1.

[0342] <Exposure and PEB>

[0343] The obtained coating film was exposed to radiation at the optimumfocusing depth with the NSR1505i6A reduction projection exposure device(of Nikon Corporation, NA=0.45, λ=365 nm). PEB was then carried out for2 minutes to make a refractive index difference between exposed andunexposed portions of the refractive index changing composition. Theamount of exposure and PEB temperature are shown in Table 2.

Example 12

[0344] Evaluations were carried out in the same manner as in Example 11except that 50 parts by weight of the compound (A-8) was used as thecomponent (A). The results are shown in Table 2.

Example 13

[0345] Evaluations were carried out in the same manner as in Example 11except that 50 parts by weight of the compound (A-9) was used as thecomponent (A). The results are shown in Table 2.

Example 14

[0346] Evaluations were carried out in the same manner as in Example 11except that 50 parts by weight of the compound (A-10) was used as thecomponent (A). The results are shown in Table 2.

Example 15

[0347] Evaluations were carried out in the same manner as in Example 11except that 50 parts by weight of the compound (B-2) was used as thecomponent (B). The results are shown in Table 2.

Example 16

[0348] Evaluations were carried out in the same manner as in Example 11except that 50 parts by weight of the compound (B-3) was used as thecomponent (B). The results are shown in Table 2. TABLE 2 transparencyamount of PEB tem- refractive index exposed unexposed exposure peratureexposed unexposed portion portion (mJ/cm²) (° C.) portion portion (%)(%) Ex. 1 80 130 1.42 1.55 99.3 99.0 Ex. 2 80 130 1.42 1.58 98.9 98.6Ex. 3 80 130 1.42 1.57 99.1 98.9 Ex. 4 80 130 1.42 1.56 99.2 99.0 Ex. 580 130 1.38 1.52 99.3 99.1 Ex. 6 80 130 1.42 1.55 99.3 99.1 Ex. 7 130 130 1.42 1.55 99.3 99.0 Ex. 8 150  100 1.42 1.55 99.3 99.0

Example 17

[0349] 50 parts by weight of the compound (A-11) as the component (A),50 parts by weight of a solution containing the polymer (B-1) as thecomponent (B) (equivalent to 50 parts by weight (solid content) of thepolymer (B-1)) and 1 part by weight of2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine as the component(C) were dissolved in diethylene glycol ethyl methyl ether to a totalsolids content of 20% and the resulting solution was filtered with amembrane filter having a pore diameter of 0.2 μm to prepare a solutionof a refractive index changing composition.

[0350] <(1) Formation of a Coating Film>

[0351] The above solution was applied to a silicon substrate with aspinner and prebaked on a hot plate at 90° C. for 2 minutes to form a1.0 μm thick coating film.

[0352] <(2) Formation of a Refractive Index Pattern>

[0353] The coating film obtained as described above was exposed to 50mJ/cm² of radiation at the optimum focusing depth with the NSR1505i6Areduction projection exposure device (of Nikon Corporation, NA=0.45,λ=365 nm). The coating film was then post exposured baked at 130°C. for 2 minutes to form a refractive index pattern having a refractiveindex difference between exposed and unexposed portions. As for therefractive index pattern formed herein, the exposed portion will bereferred to as “low-refractive index portion” and the unexposed portionwill be referred to as “high-refractive index portion” hereinafter.

[0354] <(3) Measurement of Refractive Index>

[0355] The refractive indices of the low-refractive index portion andthe high-refractive index portion of the refractive index pattern formedas described above were measured with the Auto EL IV NIR IIIellipsometer (of Rudolf Research Co., Ltd.) at 633 nm. The results areshown in Table 3.

[0356] <(4) Evaluation of Transparency>

[0357] A refractive index pattern was formed on a glass substrate in thesame manner as (1) and (2) above except that a glass substrate made fromthe Corning 1737 (of Corning Co., Ltd.) was used in place of the siliconsubstrate. The exposed portion of the refractive index pattern formed onthe glass substrate will be referred to as “low-refractive indexportion” and the unexposed portion will be referred to as“high-refractive index portion” as well hereinafter.

[0358] Then, the transmissions of the low-refractive index portion andthe high-refractive index portion of the glass substrate having thisrefractive index pattern were measured with the 150-20 Double Beamspectrophotometer (of Hitachi, Ltd.) at a wavelength of 400 to 800 nm.It can be said that when the minimum transmission exceeds 95%, thetransmission is satisfactory and when the minimum transmission is 95% orless, the transmission is unsatisfactory. The results are shown in Table3.

[0359] <(5) Stabilization>

[0360] 150 ml of phenyl glycidyl ether (containing 0.1 mmol oftetrabutylammonium bromide as a reaction catalyst) as the component (D)was heated at 100° C. and the refractive index patterns formed on thesilicon substrate and the glass substrate as described above wereimmersed in the phenyl glycidyl ether at 100° C. for 2 minutes andwashed with super pure water for 1 minute.

[0361] Then, the entire surfaces of the patterns were re-exposed to 4.5mW/cm² of radiation using the Canon PLA-501F without a filter for 1minute and heated in an oven at 200° C. for 10 minutes to stabilize therefractive index patterns.

[0362] <(6) Evaluation of Refractive Index and Transparency>

[0363] The refractive indices of the low-refractive index portion andthe high-refractive index portion of the, above stabilized refractiveindex pattern formed on the silicon substrate were measured in the samemanner as in (3) above. The results are shown in Table 4.

[0364] The transparencies of the low-refractive index portion and thehigh-refractive index portion of the above stabilized refractive indexpattern formed on the glass substrate were measured in the same manneras in (4) above. The results are shown in Table 4.

[0365] <(7) Evaluation of Stability of Refractive Index Pattern>

[0366] The entire surface of the above stabilized refractive indexpattern formed on the silicon substrate and the entire surface of theabove stabilized refractive index pattern formed on the glass substratewere exposed to 4.5 mW/cm² of radiation for 30 minutes using the CanonPLA-501F without a filter to carry out the acceleration of exposure toradiation.

[0367] The refractive indices of the low-refractive index portion andthe high-refractive index portion of the thus treated refractive indexpattern formed on the silicon substrate were measured in the same manneras in (3) above. The results are shown in Table 4.

[0368] The transparencies of the low-refractive index portion and thehigh-refractive index portion of the stabilized refractive index patternformed on the glass substrate were measured in the same manner as in (4)above. The results are shown in Table 4.

Example 18

[0369] Evaluations were carried out in the same manner as in Example 17except that 50 parts by weight of the compound (A-12) was used as thecomponent (A), the PEB temperature in the step (2) (formation of arefractive index pattern) was changed as shown in Table 3, and the typeof the component (D) and the stabilization temperature in the step (5)(stabilization) were changed as shown in Table 4. The results are shownin Table 3 and Table 4.

Example 19

[0370] Evaluations were carried out in the same manner as in Example 17except that 50 parts by weight of the compound (A-1) was used as thecomponent (A), the amount of exposure in the step (2) (formation of arefractive index pattern) was changed as shown in Table 3, and the typeof the component (D) and the stabilization temperature in the step (5)(stabilization) were changed as shown in Table4. The results are shownin Table 3 and Table 4.

Example 20

[0371] Evaluations were carried out in the same manner as in Example 17except that 50 parts by weight of the compound (A-8) was used as thecomponent (A), 5 parts by weight ofN-(2-nitrobenzyloxycarbonyl)pyrrolidine was used as the component (C),the amount of exposure in the step (2) (formation of a refractive indexpattern) was changed as shown in Table 3, and the type of the component(D) in the step (5) (stabilization) was changed as shown in Table 4. Theresults are shown in Table 3 and Table 4.

Example 21

[0372] Evaluations were carried out in the same manner as in Example 17except that a solution containing the polymer (B-2) (equivalent to 50parts by weight (solid content) of the polymer (B-2)) was used as thecomponent (B). The results are shown in Table 3 and Table 4.

Example 22

[0373] Evaluations were carried out in the same manner as in Example 17except that 1 part by weight of 4-phenylthiophenyldiphenylsulfoniumtrifluoromethanesulfonate was used as the component (C) and the amountof exposure in the step (2) (formation of a refractive index pattern)was changed as shown in Table 3. The results are shown in Table 3 andTable 4.

Example 23

[0374] Evaluations were carried out in the same manner as in Example 20except that the amount of exposure in the step (2) (formation of arefractive index pattern) was changed as shown in Table 3. The resultsare shown in Table 3 and Table 4. TABLE 3 refractive index patternformation optical properties before stabilization conditionstransparency amount of PEB refractive index low-refractivehigh-refractive exposure temperature low-refractive high-refractiveindex portion index portion (mJ/cm²) (° C.) index portion index portion(%) (%) Ex. 1 50 130 1.42 1.53 99.3 99.0 Ex. 2 50 120 1.42 1.55 99.398.6 Ex. 3 20 130 1.42 1.52 99.3 99.0 Ex. 4 80 130 1.42 1.58 98.9 98.6Ex. 5 50 130 1.42 1.52 99.3 99.1 Ex. 6 40 130 1.42 1.53 99.3 99.0 Ex. 790 130 1.42 1.58 98.9 98.6

[0375] TABLE 4 optical properties after acceleration optical propertiesafter stabilization of exposure to radiation stabilization transparencytransparency conditions refractive index low- high- refractive indexlow- high- type of low- high- refractive refractive low- high-refractive refractive component temperature refractive refractive indexportion index portion refractive refractive index portion index portion(D) (° C.) index portion index portion (%) (%) index portion indexportion (%) (%) Ex. 1 D-1 100 1.42 1.54 99.3 99.0 1.42 1.54 99.3 99.0Ex. 2 D-2  20 1.42 1.55 99.3 98.7 1.42 1.55 99.3 98.7 Ex. 3 D-2  20 1.421.54 99.3 99.0 1.42 1.54 99.3 99.0 Ex. 4 D-3 100 1.42 1.58 98.9 98.61.42 1.58 98.9 98.6 Ex. 5 D-1 100 1.42 1.54 99.3 99.1 1.42 1.54 99.399.1 Ex. 6 D-1 100 1.42 1.54 99.3 99.0 1.42 1.54 99.3 99.0 Ex. 7 D-3 1001.42 1.58 98.9 98.6 1.42 1.58 98.9 98.6

[0376] In Table 4, symbols for the component (D) denote the following.D-1: phenyl glycidyl ether (containing 10 mol % of tetrabutylammoniumbromide) D-2: 1% aqueous solution of p-xylylenediamine D-3:3-phenoxypropylene sulfide (containing 10 mol % of tetrabutylammoniumbromide)

Example 24

[0377] 50 parts by weight of the compound (A-11) as the component (A), asolution containing the polymer (B-1) (equivalent to 50 parts by weight(solid content) of the polymer (B-1)) as the component (B), 1 part byweight of 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine as thecomponent (C) and 10 parts by weight of bisphenol A diglycidyl ether asthe component (D) were dissolved in diethylene glycol ethyl methyl etherto a total solids content of 20% and the resulting solution was filteredwith a membrane filter having a pore diameter of 0.2 μm to prepare asolution of a refractive index changing composition.

[0378] The formation of a coating film, the formation of a refractiveindex pattern, the measurement of refractive index, the evaluation oftransparency and the evaluations of refractive index and transparencywere carried out in the same manner as in Example 17.

[0379] <(5) Stabilization>

[0380] The refractive index patterns formed on the silicon substrate andthe glass substrate formed as described above were heated at 150° C. (atemperature at which the component (A) did not decompose and thecomponent (A) and the component (D) reacted with each other) for 2minutes.

[0381] Then, the entire surfaces of the patterns were re-exposed to 4.5mW/cm² of radiation using the Canon PLA-501F without a filter for 1minute and heated in an oven at 200° C. for 10 minutes to stabilize therefractive index patterns.

[0382] <(7) Re-exposure and Heating>

[0383] The entire surfaces of the refractive index patterns stabilizedas described above were exposed to 4.5 mW/cm² of radiation for 1 minuteusing the Canon PLA-501F without a filter without and heated in an ovenat 200° C. for 10 minutes.

[0384] <(8) Evaluation of Stability After Re-exposure and Heating>

[0385] The refractive indices of the low-refractive index portion andthe high-refractive index portion of the re-exposed and heatedrefractive index pattern formed on the silicon substrate were measuredin the same manner as the above measurement of a refractive index (3) soas to evaluate the stability of refractive index to re-exposure andheating.

[0386] The transparencies of the low-refractive index portion and thehigh-refractive index portion of the re-exposed and heated refractiveindex pattern formed on the glass substrate were measured in the samemanner as the above evaluation of transparency (4) so as to evaluate thestability of transparency to re-exposure and heating. The results areshown in Table 5 and Table 6.

Example 25

[0387] Evaluations were carried out in the same manner as in Example 24except that 50 parts by weight of the compound (A-12) was used as thecomponent (A), the PEB temperature 3in the step (2) (formation of arefractive index) was changed as shown in table 5, and the heatingtemperature in the step (5) (stabilization) was changed as shown inTable 6. The results are shown in Table 5 and Table 6.

Example 26

[0388] Evaluations were carried out in the same manner as in Example 24except that 50 parts by weight of the compound (A-15) was used as thecomponent (A) and the amount of exposure in the step (2) (formation of arefractive index pattern) was changed as shown in Table 5. The resultsare shown in Table 5 and Table 6.

Example 27

[0389] Evaluations were carried out in the same manner as in Example 24except that 50 parts by weight of the compound (A-16) was used as thecomponent (A), 5 parts by weight ofN-(2-nitrobenzyloxycarbonyl)pyrrolidine was used as the component (C),and the amount of exposure in the step (2) (formation of a refractiveindex pattern) was changed as shown in Table 5. The results are shown inTable 5 and Table 6.

Example 28

[0390] Evaluations were carried out in the same manner as in Example 24except that a solution containing the polymer (B-2) (equivalent to50parts by weight (solid content) of the polymer (B-2)) was used as thecomponent (B). The results are shown in Table 5 and Table 6.

Example 29

[0391] Evaluations were carried out in the same manner as in Example 24except that 10 parts by weight of 1,4-bis(4,5-dihydro-2-oxazolyl)benzenewas used as the component (D) and the amount of exposure in the step (2)(formation of a refractive index pattern) was changed as shown in Table5. The results are shown in Table 5 and Table 6.

Example 30

[0392] Evaluations were carried out in the same manner as in Example 27except that 10 parts by weight of 1,4-bis(4,5-dihydro-2-oxazolyl)benzenewas used as the component (D) and the amount of exposure in the step (2)(formation of a refractive index pattern) was changed as shown in Table5. The results are shown in Table 5 and Table 6. TABLE 5 refractiveindex pattern formation optical properties before stabilizationconditions transparency amount of PEB refractive index low-refractivehigh-refractive exposure temperature low-refractive high-refractiveindex portion index portion (mJ/cm²) (° C.) index portion index portion(%) (%) Ex. 24 50 130 1.44 1.53 99.3 99.0 Ex. 25 50 120 1.44 1.55 99.398.6 Ex. 26 20 130 1.44 1.52 99.3 99.0 Ex. 27 80 130 1.44 1.58 98.9 98.6Ex. 28 50 130 1.44 1.52 99.3 99.1 Ex. 29 40 130 1.44 1.53 99.3 99.0 Ex.30 90 130 1.44 1.58 98.9 98.6

[0393] TABLE 6 optical properties after acceleration optical propertiesafter stabilization of exposure to radiation transparency transparencystabilization refractive index low- high- refractive index low- high-conditions low- high- refractive refractive low- high- refractiverefractive temperature refractive refractive index portion index portionrefractive refractive index portion index portion (° C.) index portionindex portion (%) (%) index portion index portion (%) (%) Ex. 24 2001.44 1.53 99.1 98.8 1.44 1.53 99.1 98.8 Ex. 25 140 1.44 1.54 99.1 98.51.44 1.54 99.1 98.5 Ex. 26 150 1.44 1.52 99.1 98.8 1.44 1.52 99.1 98.8Ex. 27 150 1.44 1.57 98.7 98.4 1.44 1.57 98.7 98.4 Ex. 28 150 1.44 1.5299.1 98.9 1.44 1.52 99.1 98.9 Ex. 29 150 1.44 1.53 99.1 98.8 1.44 1.5399.1 98.8 Ex. 30 150 1.44 1.57 98.7 98.4 1.44 1.57 98.7 98.4

Example 31

[0394] 50 parts by weight of the compound (A-11) as the component (A), asolution containing the compound (B-4) (equivalent to 50 parts by weight(solid content) of the compound (B-4)) as the component (B) and 1 partby weight of 4-phenylthiophenyldiphenylsulfoniumtrifluoromethanesulfonate as the component (C) were dissolved indiethylene glycol ethyl methyl ether to a total solids content of 20%and the resulting solution was filtered with a membrane filter having apore diameter of 0.2 μm to prepare a refractive index changingcomposition.

[0395] <Formation of a Coating Film>

[0396] The above solution was applied to a silicon substrate with aspinner and prebaked on a hot plate at 100° C. for 2 minutes to form a1.0 μm thick coating film.

[0397] The <Formation of a Refractive Index Pattern>, <stabilization>,<measurement of refractive index> and <evaluation of transparency> werecarried out in the same manner as in Example 17.

[0398] <Measurement of Porosity with a Mercury Porosimeter>

[0399] The porosities of the low-refractive index portion and thehigh-refractive index portion of the refractive index pattern formedabove were measured with a mercury porosimeter (Autopore 9200 ofShimadzu Corporation, the minimum measurable pore diameter of 34 Å).

[0400] <Measurement of Pore Distribution by BJH Method>

[0401] The pore distribution of the low-refractive index portion of therefractive index pattern formed above was measured by the BJH methodusing the OMNISORP 100/360 SERIES of COULTER Co., Ltd. The number ofpores having a diameter of 100 nm or more is shown in Table 8.

[0402] <Measurement of Pore Diameter by Electron MicroscopicObservation>

[0403] The diameter of each pore in the low-refractive index portion andthe high-refractive index portion of the refractive index pattern formedabove was measured by observation through a transmission electronmicroscope to count pores having a diameter of 100 nm or more per 10 μm²of an arbitrary observation range.

Example 32

[0404] Evaluations were carried out in the same manner as in Example 31except that 50 parts by weight of the compound (A-12) was used as thecomponent (A), the PEB temperature in the step (2) (formation of arefractive index pattern) was changed as shown in Table 7, and the typeof the component (D) and the stabilization temperature in the step (3)(stabilization) were changed as shown in Table 8. The results are shownin Table 7 and Table 8.

Example 33

[0405] Evaluations were carried out in the same manner as in tat Example31 except that 50 parts by weight of the compound (A-15) was used as thecomponent (A), the amount of exposure in the step (2) (formation of arefractive index pattern) was changed as shown in Table 7, and the typeof the component (D) and the stabilization temperature in the step (3)(stabilization) were changed as shown in Table8. The results are shownin Table 7 and Table 8.

Example 34

[0406] Evaluations were carried out in the same manner as in Example 31except that 50 parts by weight of the compound (A-16) was used as thecomponent (A), 5 parts by weight ofN-(2-nitrobenzyloxycarbonyl)pyrrolidine was used as the component (C),the amount of exposure in the step (2) (formation of a refractive indexpattern) was changed as shown in Table 7, and the type of the component(D) in the step (3) (stabilization) was changed as shown in Table 8. Theresults are shown in Table 7 and Table 8.

Example 35

[0407] Evaluations were carried out in the same manner as in Example 31except that a solution containing the compound (B-3) (equivalent to 50parts by weight (solid content) of the compound (B-3)) was used as thecomponent (B). The results are shown in Table 7 and Table 8. TABLE 7refractive index pattern forming stabilization conditions conditionsamount of PEB type of exposure temperature component temperature(mJ/cm²) (° C.) (D) (° C.) Ex. 31 80 100 D-1 80 Ex. 32 80 100 D-2 20 Ex.33 60 100 D-2 20 Ex. 34 100  100 D-1 80 Ex. 35 80 150 D-1 80

[0408] In Table 7, symbols for the component (D) denote the following.D-1; phenyl glycidyl ether (containing 10 mol % of tetrabutylammoniumbromide) D-2; 1% aqueous solution of p-xylylenediamine TABLE 8 porositypore transmission refractive index low-refractive high-refractivedistribution diameter of pore low-refractive high-refractivelow-refractive high-refractive index portion index portionlow-refractive low-refractive index portion index portion index portionindex portion (%) (%) index portion index portion (%) (%) Ex. 31 1.311.54 28 0 0 0 98.5 98.1 Ex. 32 1.30 1.55 30 0 0 0 98.5 98.1 Ex. 33 1.271.54 38 0 0 0 98.5 98.2 Ex. 34 1.33 1.58 22 0 0 0 98.2 97.7 Ex. 35 1.371.54 11 0 0 0 98.5 98.0

Example 36 (Production of GI Type Optical Fiber (1))

[0409] 50 parts by weight of the compound (A-6) as the component (A), 50parts by weight of a condensate of methyltrimethoxysilane (weightaverage molecular weigh of 18,000) as the component (B), 1 part byweight of 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonateas the component (C) and 1.5 parts by weight of2-(2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl)-2H-benzo triazole as anultraviolet light absorber were dissolved in methyl ethyl ketone to atotal solids content of 70%. This solution was used as a fiber stocksolution, defoamed and extruded from an injection nozzle having anopening diameter of 1.0 mm at a rate of 1 m/min, and the injected fiberwas uniformly exposed to light from a 250 mW super high pressure mercurylamp (Spot Cure of Ushio Inc., i-ray illuminance of 6.7 mW/cm²) fromtherearound using the ring light guide of Nippon PI Co., Ltd. (innerdiameter of 55 mm) and then heated at 200° C. for 5 seconds at anirradiation width of an infrared lamp of 10 cm.

[0410] An acid generated from the component (C) was mostly distributednear the surface of the fiber by exposure from therearound and furtherthe decomposition of the component (A) by heating dwindled graduallyfrom a portion near the surface to the interior, thereby producing an GItype optical fiber whose refractive index decreased in a parabolicmanner from the center axis to the periphery. When the refractive indexwas measured with an interference refractometer, the maximum refractiveindex difference Δn between the center and the periphery was 0.09.

Example 37 (Production of GI Type Optical Fiber (2))

[0411] A GI type optical fiber was produced in the same manner as inExample 36 except that 50 parts by weight of the compound (A-5) was usedas the component (A). When the refractive index of the optical fiber wasmeasured with an interference refractometer, the maximum refractiveindex difference An between the center and the periphery was 0.11.

Example 38 (Production of GI Type Optical Fiber (3))

[0412] A GI type optical fiber was produced in the same manner as inExample 36 except that 1 part by weight of2-(4-methoxyphenyl)-bis(4,6-trichloromethyl)-s-triazine was used as thecomponent (C). When the refractive index of the optical fiber wasmeasured with an interference refractometer, the maximum refractiveindex difference An between the center and the periphery was 0.09.

Example 39 (Production of GRIN Lens (1))

[0413] GRIN lenses whose refractive indices were continuouslydistributed from the center to the periphery were obtained by cuttingshort the GI type optical fibers produced in Examples 36 to 38.

Example 40 (Production of GRIN Lens (2))

[0414] 50 parts by weight of the compound (A-2) as the component (A), 50parts by weight of a condensate of methyltrimethoxysilane (weightaverage molecular weight of 18,000) as the component (B), 1 part byweight of 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonateas the component (C) and 1.5 parts by weight of2-(2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl)-2H-benzo triazole as anultraviolet light absorber were dissolved in methyl ethyl ketone to atotal solids content of 70%, and the resulting solution was formed intoa disk sample having a diameter of 2 cm and a thickness of 5 mm underreduced pressure by a hot press. The diaphragm 2which could be opened orclosed of the exposure device was installed in front of the disk sample1 as shown in FIG. 1, the disk sample was exposed to ultravioletradiation 4 having a wavelength of 365 nm and an illuminance of 30mW/cm² from the exposure device 3 by gradually opening the closeddiaphragm 2, the shutter speed was adjusted such that the diaphragm 2was fully opened in 5 seconds, exposure was completed after 5 seconds,and the disk sample was post exposured baked at 120° C. for 2 minutes.Thereby, an optically molded disk whose refractive index increasedcontinuously from the center to the periphery was obtained. Theoptically molded product had a refractive index difference of 0.08,functioned as a GRIN lens having concave lens power and showed potentialas a myopic spectacle lens.

Example 41 (Production of GRIN Lens (3))

[0415] A disk sample was obtained in the same manner as in Example 40.The top and bottom portions of the cylinder of the disk sample wereshielded from light and light could be input from the side only. In thisstate, the sample was exposed to radiation from a 250 mW super highpressure mercury lamp (Spot Cure of Ushio Inc., i-ray illuminance: 6.7mW/cm²) using the ring light guide of Nippon PI Co., Ltd. (innerdiameter of 55 mm) for 20 seconds and post exposured baked at 120° C.for 2 minutes. Thereby, an optically molded disk whose refractive indexcontinuously decreased from the center to the periphery was obtained.The optically molded product had a refractive index difference of 0.08and functioned as a GRIN lens having convex lens power.

Example 42 (Production of GI Type Optical Waveguide)

[0416] 50 parts by weight of the compound (A-2) as the component (A), 50parts by weight of a condensate of methyltrimethoxysilane (weightaverage molecular weight of 2,000) as the component (B) and 1 part byweight of 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonateas the component (C) were dissolved in diethylene glycol ethyl methylether to a total solids content of 40%, and the resulting solution wasfiltered with a membrane filter having a pore diameter of 1.0 μm toprepare a solution containing a photosensitive refractive index changingcomposition (S-1). 100 parts by weight of a condensate ofmethyltrimethoxysilane (weight average molecular weight of 2,000) usedas the component (B) and 1 part by weight of the SI-L150 (of SanshinKagaku Co., Ltd.) as a thermally acid generator were dissolved indiethylene glycol ethyl methyl ether to a total solids content of 40% toprepare a solution (S-2).

[0417] The solution (S-2) was first applied to the surface of a siliconsubstrate with a spin coater and dried at 70° C. for 10 minutes, and theentire surface of the formed coating film was exposed to ultravioletradiation having an illuminance of 4.0 mW/cm² and a wavelength of 365 nmfor 5 seconds to form a 10 μm-thick lower clad layer. Thereafter, thesolution (S-1) was applied to the lower clad layer with a spin coaterand dried at 70° C. for 10 minutes to form a 10 μm-thick intermediatelayer which was then exposed to ultraviolet radiation having anilluminance of 4.0 mW/cm² and a wavelength of 365 nm for 10 secondsthrough a photomask having an optical waveguide pattern and a width of 4to 20 μm for 10 seconds. Thereafter, the intermediate layer was postexposured baked at 120° C. for 2 minutes. The unexposed portion servedas a core portion and the exposed portion served as a side clad layer.The solution (S-2) was applied to this intermediate layer with a spincoater and dried at 70° C. for 10 minutes to form a 10 μm-thick upperclad layer whose entire surface was then exposed to ultravioletradiation having an illuminance of 4.0 mW/cm² and a wavelength of 365 nmfor 5 seconds and post exposured baked at 120° C. for 2 minutes toproduce an optical waveguide. The refractive indices for light having awavelength of 1,550 nm of the formed upper, side and lower clad layerswere 1.42. In contrast to this, the refractive index for light having awavelength of 1,550 nm of the core layer was 1.50 and the maximumrefractive index difference Δn was 0.08. As the obtained opticalwaveguide contained an optically acid generator in the upper and lowerclad layers, the diffusion of a slightly generated acid occurred at theinterfaces between the core layer and the upper clad layer and betweenthe core layer and the lower clad layer. Thereby, a refractive indexdistribution was formed at the interfaces of the upper, side and lowerclad portions with the core layer, whereby the obtained opticalwaveguide was of a GI type. As for the obtained optical waveguide, whenthe loss of the waveguide was obtained by measuring the amount of lightoutput from the other end when light having a wavelength of 1,300 nm wasinput from one end of the waveguide, it was 0.1 dB/cm or less.

Example 43 (Production of Optical Recording Medium)

[0418] 50 parts by weight of the compound (A-2) as the component (A), 50parts by weight of a condensate of methyltrimethoxysilane (molecularweight of 2,000) as the component (B) and 1 part by weight of4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonate as thecomponent (C) were dissolved in diethylene glycol ethyl methyl ether toa total solids content of 20% and the resulting solution was filteredwith a membrane filter having a pore diameter of 0.2 μm to prepare asolution containing a photosensitive refractive index changingcomposition. This solution was applied to a flat polycarbonate substratehaving a 60 nm-thick aluminum reflective film deposited by sputteringwith a spin coater and dried at 80° C. for 2 minutes to form a 1.0μm-thick refractive index changing layer. Thereafter, the refractiveindex changing layer was exposed to ultraviolet radiation having awavelength of 365 nm and an illuminance of 40 mW/cm² through a maskhaving a pitch width of 0.5 μm at a track pitch of 1.6 μm for 5 secondsand post exposured baked at 120° C. for 2 minutes. Thereby, therefractive index difference between the exposed portion and theunexposed portion was 0.08 at 633 nm and could be read perfectly as anoptical recording medium.

Example 44 (Production of Optical IC)

[0419] 50 parts by weight of the compound (A-2) as the component (A), 50parts by weight of a condensate of methyltrimethoxysilane (weightaverage molecular weight of 2,000) as the component (B) and 1 part byweight of 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonateas the component (C) were dissolved in diethylene glycol ethyl methylether to a total solids content of 33% and the resulting solution wasfiltered with a membrane filter having a pore diameter of 1.0 μm toprepare a solution containing a photosensitive refractive index changingcomposition. This solution was applied to the surface of a glasssubstrate with a spin coater and dried at 70° C. for 10 minutes, and theapplied layer was exposed to ultraviolet radiation having a wavelengthof 365 nm and an illuminance of 4.0 mW/cm² through a mask having a widthof 100 μm for 5 seconds and post exposured baked at 120° C. for 2minutes. As a result, an optical IC having a 100 μm refractive indexpattern could be obtained.

Example 45 (Production of Optical Diffraction Grating)

[0420] The solution prepared in Example 42 was used to produce a filmsample measuring 2 cm×1 cm×10 μm. This sample was exposed to ultravioletradiation having a wavelength of 365 nm and an illuminance of 4.0mW/cm². Parallel rays 9 from the exposure device 8 were reflected by areflector 7 placed at an angle of 45° and irradiated onto the filmsample 5 on a stage 6 as shown in FIG. 2. The sample was illuminatedwith an interference pattern formed by reflected light and directlyirradiated light. The sample was moved at a speed of 1 μm/min in adirection shown by an arrow in the figure upon exposure with the resultthat an optical diffraction grating having a cycle of 0.5 μm wasobtained.

Example 46 (Production of Hologram)

[0421] Parallel rays having a wavelength of 365 nm and an illuminance of4.0 mW/cm² were divided into two optical paths by a half mirror, one waslet pass through a transparent substance as signal light and wasinterfered with the other as reference light, and the obtainedinterference pattern was irradiated onto the same optically moldedproduct as in Example 45. An image of the substance recorded at a highresolution could be confirmed by illuminating the obtained opticallymolded product with light for reproduction.

1. A radiation sensitive refractive index changing compositioncomprising (A) a decomposable compound, (B) a non-decomposable compoundhaving a lower refractive index than the decomposable compound (A), (C)a radiation sensitive decomposer and (D) a stabilizer.
 2. Thecomposition of claim 1, wherein the maximum difference between therefractive index of a portion exposed to radiation and the refractiveindex of a portion unexposed to radiation is 0.02 or more.
 3. Thecomposition of claim 1 or 2, wherein the relationship between therefractive index n_(B) of the non-decomposable compound (B) and therefractive index n_(A) of the decomposable compound (A) satisfies thefollowing expression (1): n _(A) −n _(B)≧0.05  (1).
 4. The compositionof any one of claims 1 to 3, wherein the decomposable compound (A) is anacid decomposable compound, the non-decomposable compound (B) is an acidnon-decomposable polymer, and the radiation sensitive decomposer (C) isa radiation sensitive acid generating agent.
 5. The composition of claim4, wherein the acid decomposable compound (A) contains at least onecompound having at least one structure selected from the groupconsisting of structures represented by the following formulas (1) to(8):

wherein R¹ is an alkylene group, alkylene-arylene-alkylene group orarylene group, and R² is an alkylene group, alkylene-arylene-alkylenegroup, arylene group, alkylsilylene group or alkylgermylene group,

wherein M is Si or Ge, R³ is an alkylene group,alkylene-arylene-alkylene group, arylene group, alkylsilylene group oralkylgermylene group, R⁴ is an oxygen atom, alkylene group,alkylene-arylene-alkylene group, arylene group or single bond, R⁵, R⁶,R⁷ and R⁸ are each independently a hydrogen atom, alkyl group, arylgroup, alkoxy group or thioalkyl group, and m is an integer of 0 to 2,

wherein R⁹ and R¹⁰ are each independently an alkylene group,alkylene-arylene-alkylene group, arylene group, alkylsilylene group oralkylgermylene group,

wherein R¹¹ is an oxyalkylene group or single bond, and R¹² is ahydrogen atom, alkyl group, alkylene-arylene-alkylene group or arylgroup,

wherein R¹³ is a hydrogen atom, alkyl group or aryl group,

wherein R¹⁴ is an alkylene group or a structure represented by thefollowing formula (6)-1, (6)-2 or (6)-3:

wherein R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are each independently a hydrogen atom,chain alkyl group having 1 to 6 carbon atoms, chlorine atom, bromineatom, iodine atom, hydroxyl group, mercapto group, carboxyl group,alkoxyl group having 1 to 6 carbon atoms, alkylthio group having 1 to 6carbon atoms, haloalkyl group having 1 to 6 carbon atoms, haloalkoxylgroup having 1 to 6 carbon atoms, haloalkylthio group having 1 to 6carbon atoms, hydroxyalkyl group having 1 to 6 carbon atoms,mercaptoalkyl group having 1 to 6 carbon atoms, hydroxyalkoxyl grouphaving 1 to 6 carbon atoms, mercaptoalkylthio group having 1 to 6 carbonatoms, aryl group having 6 to 10 carbon atoms or aralkyl group having 7to 11 carbon atoms, —O—R¹⁹—O—  (6)-2 wherein R¹⁹ is an alkylene group,—NH—R²⁰—NH—  (6)-3 wherein R²⁰ is an alkylene group,

wherein R²¹ is an alkylene group, alkylene-arylene-alkylene group orarylene group,

wherein R²², R²³, R²⁴ and R²⁵ are each independently a hydrogen atom,chain alkyl group having 1 to 6 carbon atoms, chlorine atom, bromineatom, iodine atom, hydroxyl group, mercapto group, carboxyl group,alkoxyl group having 1 to 6 carbon atoms, alkylthio group having 1 to 6carbon atoms, haloalkyl group having 1 to 6 carbon atoms, haloalkoxylgroup having 1 to 6 carbon atoms, haloalkylthio group having 1 to 6carbon atoms, hydroxyalkyl group having 1 to 6 carbon atoms,mercaptoalkyl group having 1 to 6 carbon atoms, hydroxyalkoxyl grouphaving 1 to 6 carbon atoms, mercaptoalkylthio group having 1 to 6 carbonatoms, aryl group having 6 to 10 carbon atoms or aralkyl group having 7to 11 carbon atoms.
 6. The composition of any one of claims 1 to 3,wherein the decomposable compound (A) is a base decomposable compound,the non-decomposable compound (B) is a base non-decomposable polymer,and the radiation sensitive decomposer (C) is a radiation sensitive basegenerating agent.
 7. The composition of claim 6, wherein thedecomposable compound (A) contains at least one compound having at leastone structure selected from the group consisting of structuresrepresented by the following formulas (9) to (12):

wherein R²⁶ is an alkylene group, aralkylene group or arylene group, R²⁷is an alkylene group, aralkylene group, arylene group,alkylene-arylene-alkylene group, alkylsilylene group or alkylgermylenegroup, R²⁸, R²⁹, R³⁰ and R³¹ are each independently a hydrogen atom,alkyl group, aryl group, alkoxyl group or thioalkyl group, and i and jare each independently 0 or 1,

wherein R³² is an alkylene group, aralkylene group or arylene group, andR³³ is an alkylene group, aralkylene group, arylene group,alkylene-arylene-alkylene group, alkylsilylene group or alkylgermylenegroup,

wherein R³⁴ and R³⁵ are each independently an alkylene group, aralkylenegroup, arylene group, alkylene-arylene-alkylene group, alkylsilylenegroup or alkylgermylene group,

wherein R³⁶ and R³⁷ are each independently an alkylene group, aralkylenegroup, arylene group, alkylene-arylene-alkylene group, alkylsilylenegroup or alkylgermylene group.
 8. The composition of any one of claims 1to 7, wherein the stabilizer (D) is at least one selected from the groupconsisting of amino compound, epoxy compound, thuirane compound, oxetanecompound, alkoxymethyl melamine compound, alkoxymethyl glycolurilcompound, alkoxymethyl benzoguanamine compound, alkoxymethyl ureacompound, isocyanate compound, cyanate compound, oxazoline compound,oxazine compound and silyl compound.
 9. The composition of claim 1 whichcontains a stabilizer (D) and further a catalyst for reacting thedecomposable compound (A) with the stabilizer (D).
 10. A refractiveindex pattern forming method comprising exposing a radiation sensitiverefractive index changing composition comprising (A) a decomposablecompound, (B) a non-decomposable compound, (C) a radiation sensitivedecomposer and (D) a stabilizer to radiation and heating to react thestabilizer (D) with the decomposable compound (A) of an unexposedportion.
 11. A refractive index pattern forming method comprisingexposing a refractive index changing composition comprising (A) adecomposable compound, (B) a non-decomposable compound having a lowerrefractive index than the decomposable compound (A) and (C) a radiationsensitive decomposer to radiation through a pattern mask and treatingthe composition with a stabilizer (D) to react the decomposable compound(A) of an unexposed portion with the stabilizer (D).
 12. A refractiveindex pattern forming method comprising exposing a refractive indexchanging composition comprising (A) a decomposable compound, (B) anon-decomposable compound having a lower refractive index than thedecomposable compound (A) and (C) a radiation sensitive decomposer toradiation through a pattern mask and heating to decompose thedecomposable polymer of an unexposed portion.
 13. The method of claim10, 11 or 12, wherein the formed refractive index pattern has pores ordoes not have any pores in the exposed portion.
 14. A refractive indexpattern formed by the method of claim 10, 11, 12 or
 13. 15. Therefractive index pattern of claim 14 which consists of a first regionhaving or not having any pores and a second region having a higherrefractive index than the first region and not having any pores.
 16. Therefractive index pattern of claim 15, wherein the first region shows asmaller elastic modulus than the second region.
 17. An optical materialhaving a refractive index pattern formed by the method of claim 10, 11,12 or 13.